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Recalling adding and subtracting decimals - class-VII

Attempted 0/62 Correct 0 Score 0

$617 + 6.017 + 0.617 + 6.0017 =$?

  1. $6.2963$

  2. $62.965$

  3. $629.6357$

  4. None of these


Correct Option: C
Explanation:

 $617.00$
     $6.017$
     $0.617$
$+$ $6.0017$
-----------------
  $629.6357$
-----------------

Solve the given expression:
$3.005+4.7$

  1. $3.052$

  2. $3.475$

  3. $7.705$

  4. $3.007$


Correct Option: C
Explanation:

Addition of $3.005$ and $4.7$ gives $3.005+4.7=7.705$

Find the sum of $1.2$ and $2.3$.

  1. $35$

  2. $3.5$

  3. $0.35$

  4. $1.23$


Correct Option: B
Explanation:

The sum of $1.2$ and $2.3$ will be $1.2+2.3=3.5$

A couple has five married sons and each one of them have four children. How many members are there in the family?

  1. 10

  2. 27

  3. 30

  4. 32


Correct Option: D
Explanation:

Total member =2[2+(5×2)+(5×4)]=32

$2.\bar {3}-0.\bar {4}=$______.

  1. $1.\bar {9}$

  2. $1.\bar {8}$

  3. $1.\bar {7}$

  4. $1.\bar {6}$


Correct Option: A
Explanation:

$2.\bar{3}-0.\bar{4}=1.\bar{9}$

A train leaves the station at $8:15$ pm and reach destination at $6:25$ am . The duration of the journey is 

  1. $10$ hours $15$ minutes

  2. $9$ hours $25$ minutes

  3. $10$ hours $10$ minutes

  4. $9$ hours $40$ minutes


Correct Option: C
Explanation:

The time interval between $8:15$ pm and $6:25 am$ = $10\,\, hrs\,\, 10\,\, min$


Therefore, the duration of the journey of the train is $10\,\, hr \,\,10\,\, min.$

Therefore, option C is correct.

Find the value of $\dfrac{2}3+\dfrac {4}{3}+\dfrac{4}{5}+\dfrac{6}{5}$

  1. 4

  2. 6

  3. -4

  4. -7


Correct Option: A
Explanation:

$\dfrac 23+\dfrac 43+\dfrac 45+\dfrac 65\\dfrac {2+4}3+\dfrac {4+6}5\2+2=4$

Expressing $0.\overline { 23 } +0.2\overline { 3 } $ as a single decimal, we get

  1. $0.46\bar { 5 } $

  2. $0.4\overline { 65 } $

  3. $0.\bar { 465 } $

  4. none of these


Correct Option: B
Explanation:

$\Rightarrow$  $0.\overline {23}$ means $0.232323....$


and $0.2\bar{3}$ means $0.233333...$

$\Rightarrow$  $0.\overline {23}+0.{2\bar3}=0.23232323+0.23333333$
                            $=0.4656565$

                            $=0.4\overline {65}$

Evaluate : $0.75 - 0.0075$.

  1. $0.7405$

  2. $0.7425$

  3. $0.7415$

  4. $0.7525$


Correct Option: B
Explanation:

    $0.7500$
$-   0.0075$
______
    $0.7425$
______
$\therefore$  Required difference $= 0.7425$.

$301.01 - 0.101 = x + 198.01$

  1. $103.119$

  2. $103.101$

  3. $102.901$

  4. $102.899$


Correct Option: D
Explanation:

$x = 301.01 - 0.101 - 198.01$
   $= 301.01 - 198.111 = 102.899$

The simplified value of $\displaystyle\frac{10.24 \div 1.6}{20 - 19.8}$ is

  1. $1.6$

  2. $3.2$

  3. $16$

  4. $32$


Correct Option: D
Explanation:

$\displaystyle\frac { 10.24 }{ 1.6 } = \displaystyle\frac { 102.4 }{ 16 } = 6.4$
$\therefore \displaystyle\frac { 10.24\div 1.6 }{ 20-19.8 } = \displaystyle\frac { 6.4 }{ 0.2 } = \displaystyle\frac { 64 }{ 2 } = 32$

Simplify : $[ 0.9 - { 2.3 - 3.2 - 3.2 - ( 7.1- 5.4 - 3.5 ) } ]$

  1. 0.18

  2. 1.8

  3. 0

  4. 2.6


Correct Option: C
Explanation:

$\displaystyle \left [ 0.9-\left { 2.3-3.2-\left ( 7.1-5.4-3.5 \right ) \right } \right ]$


=$\displaystyle \left [ 0.9-\left { 2.3-3.2-\left ( 7.1-8.9 \right ) \right } \right ]$

= $\displaystyle \left [ 0.9-\left { 2.3-3.2-\left ( -1.8 \right ) \right } \right ]$

= $\displaystyle \left [ 0.9-\left { 2.3-3.2+1.8 \right } \right ]$

= $\displaystyle \left [ 0.9-\left { 4.1-3.2 \right } \right ]$

= $\displaystyle \left [ 0.9-0.9 \right ]=0 $

$\displaystyle (0.34\overline{67}+0.13\overline{33})$ is equal to 

  1. $\displaystyle 0.\overline{48}$

  2. 0.4803

  3. $\displaystyle 0.48\overline{01}$

  4. $\displaystyle 0.4\overline{8}$


Correct Option: C
Explanation:

$\displaystyle 0.34\overline{67}+0.13\overline{33}=\frac{3467-34}{9900}+\frac{1333-13}{9900}$


= $\displaystyle \frac{3433}{9900}+\frac{1320}{9900}=\frac{4753}{9900}$

= $\displaystyle \frac{4801-48}{9900}=0.4801 $

Evaluate the expression $\displaystyle 6\frac{1}{4}\times 0.25+0.75-0.3125$

  1. $5.9375$

  2. $4.2968$

  3. $2.1250$

  4. $2$


Correct Option: D
Explanation:

$\displaystyle 6\frac{1}{4}\times 0.25+0.75-0.3125$
$= 6.25 \times 0.25 + 0.75 - 0.3125$
$= 1.5625 + 0.75 - 0.3125$
$= 2.3125 - 0.3125 = 2$

The value of $\displaystyle 0.\overline{2}+0.\overline{3}+0.\overline{4}+0.\overline{9}+0.\overline{39}$ is 

  1. $\displaystyle 0.\overline{57}$

  2. $\displaystyle 1\frac{20}{33}$

  3. $\displaystyle 2\frac{1}{3}$

  4. $\displaystyle 2\frac{13}{33}$


Correct Option: D
Explanation:

$\displaystyle 0.\overline{2}+0.\overline{3}+0.\overline{4}+0.\overline{9}+0.\overline{39}$


= $\displaystyle \frac{2}{9}+\frac{3}{9}+\frac{4}{9}+\frac{9}{9}+\frac{39}{99}$

= $\displaystyle \frac{22+33+44+99+39}{99}$

= $\displaystyle \frac{237}{99}=2\frac{13}{33}$

Simplify $\displaystyle :0.\overline{4}+0.\overline{61}+0.\overline{11}-0.\overline{36}$

  1. $\displaystyle 0.\overline{83}$

  2. $\displaystyle 0.\overline{87}$

  3. $\displaystyle 0.\overline{80}$

  4. $\displaystyle 0.\overline{85}$


Correct Option: C
Explanation:

$\displaystyle :0.\overline{4}+0.\overline{61}+0.\overline{11}-0.\overline{36}=\frac{4}{9}+\frac{61}{99}+\frac{11}{99}-\frac{36}{99}=\frac{4}{9}+\frac{72}{99}-\frac{36}{99}$


$\displaystyle=\frac{4}{9}+\frac{36}{99}=\frac{44}{99}+\frac{36}{99}=\frac{80}{99}=0.\overline{80}$

In a number system the product of 44 and 11 is 3414 The number 3111 of this system when converted to the decimal number system becomes

  1. 406

  2. 1086

  3. 213

  4. 691


Correct Option: A
Explanation:

The product of 44 and 11 is 484
If base is x then 3411
$3x^3+4x^2+1x^1+4x^0=484$
$3x^3+4x^2+x=480$
This equation is satisfy when x=5
then base is 5
In decimal system number 3111 will be  written
$3\times 5^3+1\times 5^2+1\times 5^1+1\times 5^0=406$

A mathematician born in the first half of the 19th century was x years old in the year $x^2$. He was born in

  1. 1849

  2. 1806

  3. 1812

  4. 1852


Correct Option: B
Explanation:

The man born between $1800$ and $1850$ which is a perfect square. 
The perfect square number is $43 = 1849$ (Since$ 42 = 1764$ and $44 = 1936$ ) 
So in the year $1849$ the man was $43$ years old. 
Which shows the year of born is $1849 - 43 = 1806.$

$\displaystyle 8.8 =6+\frac {7} {?} $

Find $?$

  1. $2.5$

  2. $2.8$

  3. $2.2$

  4. None of these


Correct Option: A
Explanation:
Let $?$ be x
$8.8=6+\dfrac{7}{x}$

$8.8-6=\dfrac{7}{x}$

$\dfrac{7}{x}=2.8$

$\dfrac{7}{2.8}=x$

$x=\dfrac{5}{2}$

$x=2.5$
Hence option A is correct.

Difference of 32 and 27.091 is

  1. 30.791

  2. 5.909

  3. 4.909

  4. 3.909


Correct Option: C
Explanation:

32.000-27.091=4.909

So option C is the correct answer.

Sum of $1.8, 16.3$ and $72.985$ is _____ 

  1. $91.85$

  2. $9108.5$

  3. $91.085$

  4. $9.1085$


Correct Option: C
Explanation:

For obtaining the sum of decimal numbers with different decimal values we expand the decimal values of all the numbers with respect to the number with the highest decimal value. 


Because the number with the largest decimal places is $72.985$ with $3$ decimal places, we expand all numbers up to $3$ decimal places.

$1.800+16.300+72.985=91.085$

So option C is the correct answer.

Sum of 0.5, 12.56 and 0.003 is

  1. 13.063

  2. 31.063

  3. 12.063

  4. none of these


Correct Option: A
Explanation:
We know that to add numbers with different decimal places we expand all the numbers to the same decimal places by expanding zeroes.

So, the sum of 0.5 ,12.56 and 0.003 is

0.500+12.560+0.003 =13.063 

Hence, the answer is 13.063

So, option A is the correct answer.

Which number is equal to $\left (\frac {0.1}{0.01}+\frac {0.01}{0.1}\right )$?

  1. 10.1

  2. 1.10

  3. 1.01

  4. 10.01


Correct Option: A
Explanation:

$\frac {0.1}{0.01}+\frac {0.01}{0.1}=10+\frac {1}{10}$
$=10+0.1$
$=10.1$

Sum of $0.3, 0.03$ and $0.003$ is _____ 

  1. $0.999$

  2. $0.393$

  3. $0.636$

  4. $0.333$


Correct Option: D
Explanation:

To add $3$ decimal numbers of different decimal values we pick the number with the highest decimal value and expand all the other numbers to the same value by adding $0$ after the decimal point.


$0.300+0.030+0.003=0.333$


So option D is the correct answer!

The sum of two numbers is 31.021 If one of them is 11.56 then the other number is

  1. 19.461

  2. 17.461

  3. 18.641

  4. 19.561


Correct Option: A
Explanation:

The sum of two numbers $=31.021$


One of the numbers $=11.560$


Other number $=31.021-11.560=19.461$

So option A is the correct answer.

$\displaystyle 25+\frac{3}{100}+\frac{4}{1000}=$ _________

  1. 25.34

  2. 25.304

  3. 25.034

  4. 25.0034


Correct Option: C
Explanation:

$5 + \dfrac { 3}{100} + \dfrac{4}{1000}$

$= 25 + 0.03 + 0.004$
$=25.034$

Which number is equal to $\displaystyle \left ( \frac{0.1}{0.01}+\frac{0.01}{0.1} \right )?$

  1. 10.1

  2. 1.10

  3. 1.01

  4. 10.01


Correct Option: A
Explanation:

$\displaystyle \frac{0.1}{0.01}+\frac{0.01}{0.1}=10+\frac{1}{10}$
=10+0.1
=10.1

If $\displaystyle (1-1.25)N=1$, Then N=

  1. -400

  2. -140

  3. -4

  4. 4

  5. 400


Correct Option: C
Explanation:

As given,

(-0.25) $\times$ N = 1
$\rightarrow$ N = $\cfrac{1}{-0.25} $ = $-4$ (option C

$3889 + 12.952 - ? = 3854.002$

  1. $47.095$

  2. $47.752$

  3. $47.932$

  4. $47.95$


Correct Option: D
Explanation:

Let $3889 + 12.952 - x = 3854.002$.
Then $x=\left( 3889+12.952 \right) -3854.002$
             $= 3901.952 - 3854.002$
             $= 47.95$.

What is the value of $2.\overline {6} - 1.\overline (9)$

  1. $0.\overline {6}$

  2. $0.\overline {9}$

  3. $0.\overline {7}$

  4. $0.7$


Correct Option: A
Explanation:

The value of $2.\overline {6} - 1.\overline {9}$ is
$= \left (2 + \dfrac {6}{9}\right ) - \left (1 + \dfrac {9}{9}\right )$
$= \dfrac {6}{9} = 0.\overline {6}$

$3.\overline { 87 } -2.\overline { 59 } =$?

  1. $1.20$

  2. $1.\overline { 2 } $

  3. $1.\overline { 27 } $

  4. $1.\overline { 28 } $


Correct Option: D
Explanation:

$3.\overline { 87 } -2.\overline { 59 } =\left( 3+0.\overline { 87 }  \right) -\left( 2+0.\overline { 59 }  \right) $

$=\left( 3+\dfrac { 87 }{ 99 }  \right) -\left( 2+\dfrac { 59 }{ 99 }  \right) $

$=1+\left( \dfrac { 87 }{ 99 } -\dfrac { 59 }{ 99 }  \right) $

$=1+\dfrac { 28 }{ 99 } $

$=1.\overline { 28 } $.

The value of 30.5 - 30.4 + 30.3 - 30.2 + 30.1 - 30 + 29.9 - 29.8 + 29.7 - 29.6 + 29.5 - 29.4 + 29.3 - 29.2 + 29.1 - 29.0 = _________.

  1. $0.8$

  2. $0.7$

  3. $0.6$

  4. $1.8$


Correct Option: A
Explanation:

We have, $(30.5 - 30.4) + (30.3 - 30.2) + (30.1 - 30) + (29.9 - 29.8) + (29.7 - 29.6) + (29.5 - 29.4) + (29.3 - 29.2) + (29.1 - 29.0)$
$= 0.1+ 0.1 + 0.1 + 0.1 + 0.1+ 0.1 + 0.1 + 0.1$
$= 0.8$.

The value of $0.0001289-0.0000000274\times 1293+0.0000419032$ is _________?

  1. $0.0135375$

  2. $0.000153357$

  3. $135375000$

  4. $0.166632277$


Correct Option: D
Explanation:
We need to find value of$0.0001289-0.0000000274\times 1293+0.0000419032$ 
We have, $0.0001288726\times 1293.0000419032$
$=0.166632277$

What is the sum of $11.006+34+0.72$ rounded to the nearest tenths?

  1. $45.1$

  2. $45.7$

  3. $45.73$

  4. $46$


Correct Option: B
Explanation:

The sum of $11.006+34+0.72$ is $45.726$.
Now, the number $45.726$ is rounded off as $45.73$.

Again it is rounded to nearest tenths as $45.7$.

Find the value of $617+6.017+0.617+6.0017$.

  1. $6.2963$

  2. $62.965$

  3. $629.6357$

  4. $62.8975$


Correct Option: C
Explanation:

given that, $617.0000+6.0170+0.6170+6.0017=629.6357$

hence option $C$ is correct

Subtract the given decimals: $4.17$ from $5.5$ 

  1. $1.33$

  2. $3.62$

  3. $1.12$

  4. $3.15$


Correct Option: A
Explanation:

$5.5-4.17=1.33$

The value of $(1.02)^4+(0.98)^4$ upto three places of decimal is

  1. $2.004$

  2. $2.003$

  3. $2.04$

  4. $2.0004$


Correct Option: A
Explanation:

${\left( 1.02 \right)}^{4} + {\left( 0.98 \right)}^{4}$

$= {\left( 1 + 0.02 \right)}^{4} + {\left( 1 - 0.02 \right)}^{4}$
$= \left[ {^{4}{C} _{0}} {\left( 1 \right)}^{4} + {^{4}{C} _{1}} {\left( 1 \right)}^{4-1} {\left( 0.02 \right)}^{1} + {^{4}{C} _{2}} {\left( 1 \right)}^{4-2} {\left( 0.02 \right)}^{2} + {^{4}{C} _{3}} {\left( 1 \right)}^{4-3} {\left( 0.02 \right)}^{3} + {^{4}{C} _{4}} {\left( 1 \right)}^{4-4} {\left( 0.02 \right)}^{4} \right] + \ \left[ {^{4}{C} _{0}} {\left( 1 \right)}^{4} - {^{4}{C} _{1}} {\left( 1 \right)}^{4-1} {\left( 0.02 \right)}^{1} + {^{4}{C} _{2}} {\left( 1 \right)}^{4-2} {\left( 0.02 \right)}^{2} - {^{4}{C} _{3}} {\left( 1 \right)}^{4-3} {\left( 0.02 \right)}^{3} + {^{4}{C} _{4}} {\left( 1 \right)}^{4-4} {\left( 0.02 \right)}^{4} \right]$
$= 2 \left[ {^{4}{C} _{0}} + {^{4}{C} _{2}} \left( 0.0004 \right) + {^{4}{C} _{4}} \left( 0.00000016 \right) \right]$
$= 2 \times \left( 1 + 0.0024 + 0.00000016 \right)$
$= 2 \times 1.002$
$= 2.004$
Hence the value of given expression upto three places of decimal is $2.004$.

The value of $0.\overline{1}+0.0\overline{1}+0.00\overline{1}$ is equal to

  1. $\dfrac{343}{900}$

  2. $\dfrac{37}{300}$

  3. $\dfrac{4}{33}$

  4. $\dfrac{1343}{10989}$


Correct Option: B
Explanation:
Let $  x = 0.\bar{1} \Rightarrow 10x = 1.\bar{1}$

$ 10x -x = 1 \Rightarrow  x = 1/9 ...(I)$

$ y = 0.0\bar{1} = 0.01+0.001+0.0001+...$

$ = \dfrac{1}{100}+\dfrac{1}{1000}+\dfrac{1}{10000}+...$

$ = \dfrac{1}{100}(1+\dfrac{1}{10}+\dfrac{1}{100}+...)$

$ = \dfrac{1}{100}\times \dfrac{1}{1-\dfrac{1}{10}} = \dfrac{1}{90}...(II)$

$ z = 0.00\bar{1} = 0.001+0.0001 + 0.00001+...$

$=0.001(1+\dfrac{1}{10}+\dfrac{1}{100}+...)$

$ =\dfrac{1}{1000}\times \dfrac{1}{1-\frac{1}{10}}  = \dfrac{1}{1000} \times \dfrac{10}{9} = \dfrac{1}{900}...(III)$

From (1),(2),(3) $ 0.\bar{1}+0.0\bar{1}+0.00\bar{1} = \dfrac{1}{9}+\dfrac{1}{90}+\dfrac{1}{900}= \dfrac{111}{900} = \dfrac{37}{300}$

$ \therefore $ option B is correct

The width of the class  $55.5 - 60.5$  is

  1. $10$

  2. $5$

  3. $2.5$

  4. $7$


Correct Option: B
Explanation:

Width of class $=U.L-L.L=60.5-55.5=5$

A flask weighs $64.27\,g$ when empty and $150.35\,g$ when full of water, Find the wight when it is $0.75$ times full of water.

  1. $128.83\,g$

  2. $120\,g$

  3. $150\,g$

  4. $73.3\,g$


Correct Option: A

Vanmathi bought $4$ books each weighing $500\ g$. The weight of $4$ books is $2\ kg$.

  1. True

  2. False


Correct Option: A

Simplify the following :

$0.4 \times \displaystyle \frac{7}{3} \div \frac{15}{8}  $ of $  \left ( \dfrac{7}{5} - \dfrac{4}{3} \right )$.

  1. $\displaystyle 5 \frac{8}{3375}$

  2. $\displaystyle 7 \frac{8}{15}$

  3. $\displaystyle 7 \frac{7}{15}$

  4. $\displaystyle 5 \frac{7}{3375}$


Correct Option: C
Explanation:

The given expression is

$0.4\times \dfrac { 7 }{ 3 } \div \dfrac { 15 }{ 8 } $ of $\left( \dfrac { 7 }{ 5 } -\dfrac { 4 }{ 3 }  \right) $

$=\dfrac { 4 }{ 10 } \times \dfrac { 7 }{ 3 } \div \dfrac { 15 }{ 8 } $ of $\dfrac { 1 }{ 15 } $

$ =\dfrac { 2 }{ 5 } \times \dfrac { 7 }{ 3 } \div \dfrac { 1 }{ 8 } $

$ =\dfrac { 2 }{ 5 } \times \dfrac { 7 }{ 3 } \times \dfrac { 8 }{ 1 } $

$ =\dfrac { 112 }{ 15 } $

$=7\dfrac { 7 }{ 15 } $

The simplification of
$2.002+7.9\left{ 2.8-6.3\left( 3.6-1.5 \right) +15.6 \right} $ yields

  1. 2.002

  2. 4.2845

  3. 40.843

  4. 42.845


Correct Option: D
Explanation:

$2.002+7.9\left{ 2.8-6.3\left( 3.6-1.5 \right) +15.6 \right} $
$=2.002+7.9\left{ 2.8-6.3\times 2.1+15.6 \right} $
$=2.002+7.9\left{ 2.8-13.23+15.6 \right} $
$=2.002+7.9\left{ 5.17 \right} $
$=2.002+40.843=42.845$

Solve : $25 +\displaystyle{\frac{3}{100}}+\displaystyle{\frac{4}{1000}}=$ ?

  1. $25.34$

  2. $25.304$

  3. $25.034$

  4. $25.0034$


Correct Option: C
Explanation:

The value of $25 $ $+$ $\displaystyle{\frac{3}{100}}$ $+$ $\displaystyle{\frac{4}{1000}}$ is

$=25+0.03+0.004$
$= 25.034$

Which number is equal to $\displaystyle{\left(\frac{0.1}{0.01} + \frac{0.01}{0.1}\right)}$ ?

  1. $10.1$

  2. $1.10$

  3. $1.01$

  4. $10.01$


Correct Option: A
Explanation:

$\displaystyle{\frac{0.1}{0.01} + \frac{0.01}{0.1}}$ = 10 + $\displaystyle{\frac{1}{10}}$ $= 10 + 0.1 = 10.1$

3 tens 6 thousandths is

  1. $30.6$

  2. $30.06$

  3. $310.6000$

  4. $30.006$


Correct Option: D
Explanation:

3 tens 6 thousandths is

$=30+\dfrac{6}{1000}=30+0.006=30.006$

$58 +\displaystyle{\frac{3}{100}}+\displaystyle{\frac{7}{1000}}=?$

  1. $58.0037$

  2. $58.37$

  3. $58.037$

  4. none


Correct Option: C

If $28052 \div 55= 1100,$ then $280.5\div 25.5 =$ ?

  1. $1.1$

  2. $1.01$

  3. $0.11$

  4. $11$


Correct Option: D
Explanation:

$\displaystyle{\frac{280.5}{25.5}}$ = $\displaystyle{\frac{280.5}{25.5} \times \frac{10}{10} \times \frac{10}{10} = \frac{2805}{2.55} \times \frac{1}{100} = \frac{1100}{100}}$ = 11

Find the values of $\displaystyle \frac{0.34-0.034}{0.00\div 34}$

  1. $0.306$

  2. $306$

  3. $3060$

  4. $0.0306$


Correct Option: C
Explanation:

$\displaystyle \frac{0.34-0.034}{0.0034\div 34}=\frac{0.306}{0.0001}=\frac{0.3060}{0.0001}$

$=\displaystyle \frac{3060}{1}=3060 $

The value of $\displaystyle \frac{0.25\times0.25-0.24\times0.24}{0.49}=?$

  1. $0.0006$

  2. $0.49$

  3. $0.01$

  4. $0.1$


Correct Option: C
Explanation:

Given, $\displaystyle \frac {0.25\times0.25-0.24\times0.24}{0.49}$

Using the identity $a^2 - b^2 = (a+b)(a-b)$
$\therefore \displaystyle 0.25\times 0.25 - 0.24\times 0.24 = (0.25+0.24)(0.252-0.24) = (0.49)(0.01)$

Thus, $\displaystyle \frac {0.25\times0.25-0.24\times0.24}{0.49} = \frac {0.49\times 0.01}{0.49}$ = $0.01$

$\displaystyle \frac{42.31-26.43}{42.31+26.43}\div \frac{423.1-264.3}{4.231+2.643}$  is equal to 

  1. $\displaystyle 10^{-2}$

  2. $\displaystyle 10^{-1}$

  3. 10

  4. $\displaystyle 10^{2}$


Correct Option: A
Explanation:

$\displaystyle \frac{42.31-26.43}{42.31+26.43}\div \frac{423.1-264.3}{4.231+2.643}$

$=\displaystyle \frac{15.88}{68.74}\div \frac{158.8}{6.874}$

$=\displaystyle \frac{15.88}{68.74}\times \frac{6.874}{158.8}=\frac{1588}{6874}\times \frac{68.74}{1588}$

= $\displaystyle \frac{68.74}{6874}=\frac{6874}{687400}=\frac{1}{100}=0.01$

Which pair of operations will make the equation below true when inserted into the blank spaces in the order shown? $\displaystyle 2\frac{3}{10} $      $1.5$  _  $2=1.8$

  1. $-$ and $+$

  2. $\displaystyle \times $ and $+$

  3. $+$ and $-$

  4. $\displaystyle \times $and $-$


Correct Option: C
Explanation:

Let us first write the mixed fraction $2\dfrac {3}{10}$ in decimals as follows:


$2\dfrac { 3 }{ 10 } =\dfrac { (2\times 10)+3 }{ 10 } =\dfrac { 20+3 }{ 10 } =\dfrac { 23 }{ 10 } =2.3$

Therefore, $2\dfrac {3}{10}=2.3$

Now, add $1.5$ to $2.3$ then we get,

$2.3+1.5=3.8$

Now subtract $2$ from $3.8$ as follows:

$3.8-2=1.8$

Therefore, we have $2.3+1.5-2=1.8$

Hence, $2\dfrac { 3 }{ 10 } +1.5-2=1.8$

In the expression $24 - [ 2.4 - { 0.24 - (0.024 - x)}] = 21.8184$, the value of x is 

  1. $0.0024$

  2. $0.024$

  3. $0.24$

  4. $2.4$


Correct Option: A
Explanation:

We solve the given expression as follows:


$24−\left[ 2.4−{ \left{ 0.24−\left( 0.024−x \right)  \right}  } \right] =21.8184\ \Rightarrow 24−\left[ 2.4−{ \left{ 0.24−0.024+x \right}  } \right] =21.8184\ \Rightarrow 24−\left[ 2.4−{ \left{ 0.216+x \right}  } \right] =21.8184\ \Rightarrow 24−\left[ 2.4−{ 0.216-x } \right] =21.8184$
$\Rightarrow 24−\left[ 2.184-x \right] =21.8184\ \Rightarrow 24−2.184+x=21.8184\ \Rightarrow 21.816+x=21.8184\ \Rightarrow x=21.8184-21.816\ \Rightarrow x=0.0024$

Hence, $x=0.0024$

The simplification of $\displaystyle3\overline{36}-2.\overline{05}+1\overline{33}$ is equal to

  1. 2.6

  2. 2.64

  3. $\displaystyle 2.\overline{61}$

  4. $\displaystyle 2.\overline{64}$


Correct Option: D
Explanation:

$\displaystyle 3.\overline{36}-2.\overline{05}+1.\overline{33}$


= $\displaystyle 3+0.\overline{36}-\left ( 2+0.\overline{05} \right )+1+0.\overline{33}$

= $\displaystyle 3+\frac{36}{99}-2-\frac{5}{99}+1+\frac{33}{99}$


= $\displaystyle 2+\frac{64}{99}=2+0.\overline{64}=2.\overline{64}$

Evaluate: $515.15-15.51-1.51-5.11-1.11.$

  1. $491.91$

  2. $419.91$

  3. $499.19$

  4. $411.19$


Correct Option: A
Explanation:

$515.15-15.51-1.51-5.11-1.11.$

$=515.15 - (15.51 + 1.51 + 5.11 + 1.11)$
$= 515.15 - 23.24$
$=491.91$

If k is an integer and $\displaystyle \left( 0.0025 \right) \left( 0.025 \right) \left( 0.00025 \right) \times { 10 }^{ k }$ is an integer, what is the least possible value of k ?

  1. -12

  2. -6

  3. 0

  4. 6

  5. 12


Correct Option: E
Explanation:

Given expression:

 $(25 \times 10^{-4}) $ $(25 \times 10^{-3}) $$(25 \times 10^{-5}) $
$\rightarrow$ $15625 \times 10^{-12}$.
So, to make the result an integer, we must multiply by $10^{12}$
Least possible value of k should be 12. (option E)

Match the following.

Column I Column II
(i) $715+12.59+685.35=$ (P) $417.16$
(ii) $518-( 216.80 -115.96 )=$ (Q) $213.07$
(iii) $4.090+0.050+6.500=$ (R) $1412.94$
(iv) $36.050+198.05-21.03=$ (S) $10.640$
  1. (i)$\rightarrow$ (Q), (ii) $\rightarrow$ (R), (iii)$\rightarrow$ (S), (iv) $\rightarrow$ (P)

  2. (i)$\rightarrow$ (R), (ii) $\rightarrow$ (P), (iii) $\rightarrow$(S), (iv) $\rightarrow$(Q)

  3. (i)$\rightarrow$ (R), (ii)$\rightarrow$(S), (iii) $\rightarrow$ (P), (iv) $\rightarrow$ (Q)

  4. (i)$\rightarrow$ (Q), (ii) $\rightarrow$(S), (iii) $\rightarrow$ (P), (iv)$\rightarrow$(R)


Correct Option: B
Explanation:

(I) $715+12.59+685.35=1412.94$
(II) $518-(216.80-115.96)=518-100.84=417.16$
(III) $4.090+0.050+6.500=10.640$
(IV) $36.050+198.05-21.03=213.07$.

The base of the decimal number system is ten, meaning, for example, that 123=1.10$^{2}$ + 2.10 + 3.
In the binary system, which has base two, the first five positive integers are 1,10,11,100,101. The numeral 10011 in the binary system would then be written in the decimal system as:

  1. 19

  2. 40

  3. 10011

  4. 11

  5. 7


Correct Option: A
Explanation:

binary(10011)= (1)*2^4 + (0)*2^3 + (0)*2^2 + (1)*2^1 + (1)*2^0

                     =16 + 0 + 0 + 2 + 1
                     =19.

If $1.8 - 6.3x = -0.3x$, then find the value of $x$ is


  1. $x=0.3$

  2. $x=0.6$

  3. $x=0.7$

  4. $x=0.5$


Correct Option: A
Explanation:

from question 

$1.8-6.3x=-0.3x$

$\Rightarrow6.3x -0.3x =1.8$

$\Rightarrow6.0x =1.8$

$\Rightarrow x =\dfrac{1.8}{6}$

$x = 0.3$

$\text{Option A is correct.}$

Evaluate: $3.7-1.9$

  1. $0.6$

  2. $7.3$

  3. $3.4$

  4. $1.8$


Correct Option: D
Explanation:

$3.7-1.9$


$=\dfrac{37}{10}-\dfrac{19}{10}=\dfrac{37-19}{10}$


$=\dfrac{18}{10}=1.8$

Sum of $0.5, 12.56$ and $0.003$ is:

  1. $13.063$

  2. $31.036$

  3. $12.063$

  4. $12.036$


Correct Option: A
Explanation:

The sum of $0.5 ,12.56$ and $0.003$ is

$0.5+12.56+0.003$ $=13.063$ 
Hence, the answer is $13.063$.

The charges in a resort are shown.
Mr. Mohit drove to the resort with his wife and three children on Saturday at $1:30$p.m. They left the resort at $8$ p.m. How much did Mr. Mohit and his family have to pay in all?

Entrance Fee Rs. $40$ per car
Monday to Friday Rs. $15.50$ per passenger
Saturday and Sunday Rs. $22.50$ per passenger
Parking charges Rs. $10.60$ per half hour


  1. Rs. $250.30$

  2. Rs. $300.90$

  3. Rs. $267.80$

  4. Rs. $290.30$


Correct Option: D
Explanation:

Total number of members in family $\rightarrow$ $5$

Time they spent at the resort $\rightarrow$ $6.5$ hr
Entrance fee $\rightarrow$ $40$
Charge of the members $\rightarrow$  ($22.5$$\times$$5$) $\rightarrow$ $112.5$
Parking charges $\rightarrow$ ($13$$\times$$10.60$) $\rightarrow$ $137.80$ (we took $13$ Since charges are given for half an hour)
Total amount to be paid $\rightarrow$ $40$ + $112.5$ + $137.80$ $\rightarrow$ $290.30$
Hence, Option D is correct answer.


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