Calculations and mental strategies 1 - class-VIII
Description: calculations and mental strategies 1 | |
Number of Questions: 116 | |
Created by: Saurabh Mittal | |
Tags: simple equations simple linear equations expressions and formulae equation calculations and mental strategies 1 linear equation in one variable pairs of equations linear equations in one variable maths equations equations and inequalities linear equation formation of an equation and its solution |
Four years ago, the father's age was three times the age of his son. The total of the age of the father and the son after four years will be $64$ years. What is the father's age at present?
The area of a field in the shape of a trapezium measures $1440{m}^{2}$. The perpendicular distance between its parallel sides is $24m$. If the ratio of the parallel sides is $5:3$, the length of the longer parallel side is:
If $\left(\dfrac { 3 } { 4 }\right)^{th}$ of $x$ of $\left(\dfrac { 1 } { 4 }\right)^{th}$ of $35600 = 1668.75 ,$ find $x$
If a function $f$ is linear with $f(0)=5$ and $f(2)=9$ then find $f(9)$
If $(30 + x) : (23 + x) = 5 : 4$ then find the value of x.
Translate the following sentence into an algebraic equation: "13 diminished from twice a number is equal to 17"
'8 is less than twenty times a' is written as
Algebraic expression for the statement 8 times a taken away from 60
The equation for the statement : 'half of a number added to 20 is 25'
Equation of the statement : 'Thrice the length of a room is $240$ metres.'
Equation for the statement: 'thrice the length (L) of a room is 340 metres'
The equation for the statement:"half a number added to 10 is 15".
In three coloured boxes - Red, Green and Blue, $108$ balls are placed. There are twice as many balls in the green and red boxes combined as there are in the blue box and twice as many in the blue box as there are in the red box. How many balls are there in the green box?
The following expressions in statement is given as:
$x+3$
The following expressions in statement is given as:
$y-7$
The $ \dfrac{x}{5}$ expression in the statement is given as $x$ is divided by $5$.
Twelve less than $3$ times a number is $27$. The number is ___________.
The equation for the statement; 'Half of a number added to $10$ is $15$' is __________.
Kapil bought some packets of pens. He bought one packet containing $5$ pens and $n$ packets containing $2$ pens each. Which of the following expressions could be used to find the total number of pens that Kapil bought ?
If five times of a number is $80$, then the number is ________.
Anu had 6 pairs of shoes. She let Mohit borrow $x$ pairs of shoes, and then she had 4 pairs left. Which equation model shows this solution ?
Jaya's score in Mathematics is $30$ more than two third of her score in English. If her score in English is $x$, find her score in Mathematics.
Preeti travelled $3x$ km distance by walk, $9y$ km by cycle and $5$ km by bus. The total distance covered by Preeti is ____________.
Meera bought packs of trading cards that contain $10$ cards each. She gave $7$ cards to her friend.
$x =$ Number of packs of trading cards
Which expression shows the number of cards left with Meera?
The algebraic expression for the statement 'thrice of $x$ is added to $y$ multiplied by itself' is __________.
Aanya got $5$ marks in Science test. Her friend Sneha got $'x'$ marks more than Aanya. How many marks did they get altogether?
Match the following.
Column - I | Column II | ||
---|---|---|---|
(i) | The total mass of $3$ boxes is $5\ kg$. The mass of two of the boxes is $x\ kg$ each. The mass of third box is | (a) | $x - 11$ |
(ii) | Sid had $x$ eggs. He used $5$ eggs to bake a cake and gave $6$ eggs to his neighbour. The number of eggs left with him is | (b) | $\dfrac {x}{3}$ |
(iii) | Mohit had $Rs. x$. He gave the money to his $3$ sisters equally. Each girl get Rs. | (c) | $5 - 2x$ |
Find the cost of $3$ notebooks and $1$ magazine in terms of y, if the cost of $1$ notebook is Rs.$2y$ and that of $1$ magazine is $Rs. (y+3)$.
In the last three months Mr.Sharma lost $5\frac{1}{2}$kg, gained $2\frac{1}{4}$ kg and then lost $3\frac{3}{4}$ kg weight. If he now weighs $95$kg, then how much did Mr.Sharma weighs in beginning?
In an alloy of zinc, tin and lead, quantity of zinc is $\left(\cfrac{3}{4}\right)^{th}$ that of tin and quantity of tin is $\left(\cfrac{4}{5}\right)^{th}$ that of lead. How much of each metal will be there in $12$ kg of the alloy?
For a journey the cost of a child ticket is $\cfrac { 1 }{ 3 } $ of the cost of an adult ticket. If the cost of tickets for $4$ adults and $5$ children is Rs. $85$, the cost of a child ticket is
If $2x + 2(4 + 3x) < 2 + 3x > 2x + \dfrac{x}{2}$ then $x$ can take which of the following values.
Divide $Rs\ 1,545$ between three people $A,B$ and $C$ such that $A$ gets three-fifths of what $B$ gets and the ratio of the share of $B$ to $C$ is $6:11$.
what amount will each person get ?
If $(a+b):(b+c):(c+a)=6:7:8$ and $(a+b+c)=14$ , then the value of $c$ is
In a two digit no. the digit at units place is $\left| x-2 \right| $ and digit at tens place is $\left| x+1 \right| $, then that number is
if $76$ is divided into four parts proportional to $7,5,3.4$ then the smallest part is:
The ratio of the volumes of water and glycerine in 240cc of mixture is 1:3 .The quantity of water (in cc) that should be added to the mixture so the volumes of water and glycerine 2:3 is:
$8$% of the voters in an election did not cast their votes. In this election, there were only two candidates. The winner by obtaining $48$% of the total votes, defeated his contestant by $1100$ votes. The total number of voters in the election was?
Which of the equation satisfy the given statement ?
"Perimeter of an equilateral triangle is three times its side l"
Equation of the statement 'Thrice the length (l) of room is $340$ metres' is ____
An algebraic expression, $11-y$ can be written in the statement form as ____
If fives of a number is $80$, then the number is ___
If a $\in { 1,2,3,4 } ,$ then number of equations of the form $x ^ { 2 } + a x + 1 = 0$ having real roots is
The difference between a two-digit number and the number obtained by interchanging the positions of its digits is 36. What is the difference between the two digit of that number ?
The sum of the digit of a two-digit number is $\frac { 1 }{ 5 } $ of the difference between the number and the number obtained by interchanging the positions of the digit. What is definitely the difference between the digit of that number ?
The sum of the digits of a two-digit number is 9 less then the number. Which of the following digits is at unit's place of the number ?
Get the algebraic expression in the following cases using variables, constant and arithmetic operations.
Subtraction of $z$ from $y$.
Two years ago the mean age of $40$ people was $11$ years. Now a person left the group and the mean age is changed to $12$ years, then the age of the person who left the group is?
Five years ago Anjali's age was twice Sarita's age. Five years hence, their ages will be $4 : 3$. Anjali's present age is
Kiran is 24 years older than Rakesh. 10 years back Evans age was five times the age of Rakesh. Find the present age of Rakesh.
A game is played by three players. The loser has to triple the money of each of the other players has. Three games are played and each one losses a game. At the end all have the same amount namely $Rs.\ 54$. The amount the first loser has at the begining is
When a two digit number is reversed, the new number is reduced by $63$ and the sum of digits of these individual numbers is $9$. Now, if these numbers are converted into base $'x'$ the larger number becomes $5$ times that of smaller one, then the value of $x$ is :
A tree, in each year, grows $5\ cm$ less than it grew in the previous year. If it grew half a meter per year, then the height of the tree (in meters), when it ceases to grow, is
The sum of present ages of a father and his son is $10$ years more than the present age o mother. If the mother is $15$ years older than the son, then find the age of father after $5$ years.
If a number, when divided by $4$, is reduced by $21$, the number is:
The product of two numbers is 1296. If one number is 16 times the other, then the two numbers are
The average age of the mother and her six children is 12 years which is reduced by 5 years if the age of mother is excluded. How old is the mother?
Two years ago, a father was five times as old as his son. Two years later, father age will be 8 more than three times the age of the son. Find the sum of present ages of father and son.
If the sum of five consecutive even numbers is $240$ then find the middle number.
If $50$ is subtracted from two-third of a number, the result is equal to sum of $40$ and one-fourth of that number. What is the number?
The average of 9 consecutive numbers with difference of 9 is 79 , then with smallest number among them ?
The two parts of $100$ for which the sum of double of first and square of part is minimum. value of the smaller part is:
find the sum of two numbers ,whose ratio is 7:19 and their difference is 12
A number is $\dfrac{2}{5}$ of the second number seum of the two number is $70$; then the number are
In an examination Karan got $10$ marks more than Bhavna. Isha got $5$ marks less than Bhavna. If Trio get a total of $170 ,$ then what is the marks obtained by Isha?
Half the number is added to $18$, then sum is $46$, find the number?
After $12$ years I shall be $3$ times as old as I was $4$ years ago. Find my present age.
If six times of a number is $48$, then the number is
The number of girls in a class is $5$ times the number of boys.Which of the following can be the total number of children in a class?
Rams age is $1/3$ of his fathers age. Rams fathers age will be $12$ years more than twice of Shyams age after $10$ years. If Shyams $8th$ bright day was celebrated $3$ years before, then what is Rams age at present?
If $x$ toffees are distributed equally among $5$ children, then each child gets $5x$ toffees.
In a two digits number, the digit at tens place is $7$ times the digits at unit place, then the number is
$15$ years hence a men will be just $4$ times as old as he was $15$ years ago. His present age is _________ years
If the sum and the product of the digits of two digit number is the same, then the number is_____________
The number of different necklaces formed by using $2n$ identical diamonds and $3$ different jewels when exactly two jewels are always together is ____________.
20 years ago when my parents got married their average age was 23 years, now the average age of my family consisting of my self and my parents is 34 years, then my present age is?
If $12$ years hence of Ravi will he $9$ times his age $12$ years ago, find the present age of Ravi
$A$ is $3$ times as old as $B$ and $C$ together. If after $10$ years $A's$ age would be equal sum of the ages of $B$ and $C .$ find the present age of $A$
The number of students scoring less than 60 marks is ___________.
The number of students scoring less than 80 marks but not less than 40 marks is _______.
Three times a number is equal to two times of the other. Find the ratio of 3 times the sum and 5 times the difference of the two numbers.
In a two-digit number, the tens digit is one more than twice the units digit. The sum of the digits is $36$ less than the number formed by reversing the digits. Find the product of the digits.
There are m men and two women participating in a chess tournament. Each participate plays two games with every other participant. If the number of games played by the men between themselves exceeds the number of games played between the men and the women by $84$, then the value of m is?
x years ago, the difference between the ages of Hari and Sadu was y years. Then after z years what will be the difference between their ages?
The present age of Sohan is $20$ years more than the present age of Sachin. $3$ years hence, it will be thrice that of Sachin. Find the present age of Sohan.
There are $2$ boxes A and B. If we take out $10$ apples from A box & put these apples in B box then the number of apples in B box will be $4$ times of A box. If we take out $5$ apples from B box & put these apples into A box then the number of apples in both A & B boxes will be same in numbers. Find out the total apples in both the boxes :
In an examination, the ratio of passes to failures was 4 : 1. Had 30 less appeared and 20 less passed, the ratio of passes to failures would have been 5 : 1. Find the number of students who appeared for the examination.
$A$ is older than $B$. Taking present ages of $A$ and $B$ as $x$ years and $y$ years respectively, find in terms of $x$ and $y$. The difference between the ages of A and B.
A boy was asked to multiply a certain number by $25$. He multiplied it by $52$ and got his answer more than the correct one by $324$. The number to be multiplied was:
An old rhyme and problem:
A can do a piece of work in $24$ days. If B is $60\%$ more efficient then the number of days required by B to do the twice as large as the earlier work is-
A and B can do a job in $12$ days, B and C can do it in $16$ days. After A has worked for $5$ days and B has worked for $7$ days, C can finish the rest in $13$ days. In how many days can C do the work alone?
A thief escaped from police custody. Since he was sprinter he could clock $40\ km/hr$. The police realized it after $3$ hr and started chasing him in the same direction at $50\ km/hr$. The police had a dog which could run at $60\ km/hr$. The dog could run to the thief and then return to the police and then would turn back towards the thief. If kept on doing so till the police caught the thief. Find the total distance travelled by the dog in the direction of the thief.
Grass in lawn grown equally thick and in a uniform rate. It takes $24$ days for $70$ cows and $60$ days for $30$ cows to eat the whole of the grass. How many cows are needed to eat the grass in $96$ days?
A large tanker can be filled by two pipes A and B in 60 minutes and 40 minutes respectively. How many minutes will it take to fill the empty tanker if only B is used in the first-half of the time and A and B are both used in the second-half of the time?
Two birds are flying in opposite directions over the edge of a circle-shaped forest of radius 4 km. Both start off from the same point simultaneously and both have to go to the same nest. Who reaches the nest first?
I. Speed of bird A is 60 km/hr and speed of bird B is 50 km/hr.
II. The nest is diametrically opposite to the starting point of the flight of the two birds, on the circumference of the forest.
To find the present age of Rishi, which statements can be dispensed.
I. In ten years,Richard will be twice as old as Rishi was 10 years ago.
II. Richard is now 9 years older than Rishi.
III. Five years ago, Rishi was 9 years younger than Richard.
Helen is determining how much money she and her friends will need to go for a movie.
Each person going will buy a ticket, a bag of popcorn, and a drink. Helen writes the given formula that will represent the situation.
$m = q (t + p + d)$
Which description represents the meaning of the variable $q$?
A clock is set right at $8:00\ a.m$. The clock gains $10$ minutes in $24$ hours. What will be the right time when this clock indicates $1\ p.m$ on the following day?
Three years ago, the average age of the family of 5 members was 17 years. A baby having been born, the average age of the family is the same today. What is the baby today?
Henry just set up direct deposit from his employer to his checking account. The equation $\displaystyle y=360x-126.13$ represents the balance in Henry's account if he deposit his weekly paycheck for x weeks. Based on this equation, which of the following statements is true
Ajit is $21$ years younger than his father. What is their total age in $7$ years time?
Reema bought $x$ pens at Rs.$2.60$ each and $y$ greeting cards at $80$ paise each. If the pens cost Rs.$12$ more than the cards, the equation involving $x$ and $y$ is
Equation for the statement 'Thrice the length ($l$) of a room is $340$ metres' is _____ .
Ashima bought $23$ things from the market. She bought five more jeans than shirts and two fewer watches than jeans. If $x$ represents the number of shirts in total, then which sentence can be used to find how many of each thing are bought?
You are decorating a gift pack with 15 flowers. You want an equal number of flowers in each of the 3 rows on the gift pack. Which equation would you use to find the number of flowers, r, in each row?
A shopkeeper sells bananas in two types of boxes, one small and one large. A large box contains as many as 6 small boxes plus 2 loose bananas. Form an equation which gives the number of bananas in each small box, if the number of bananas in 1 large box is 50.
The teacher tells the class that the highest marks obtained by a student in her class is four times the lowest marks plus 6. The highest score is 65. Form the equation which will calculate the lowest marks.
Ram's father's age is 3 years more than two times Ram's age. Ram's father is 45 years old. Form an equation to find Ram's age.
A group of students decided to collect as many paise from each member of the group as is the number of members in the group. If the total collection amounts to Rs.$22.09$, the number of members in the group is.
Each child from a certain school can make $5$ items of handicraft in a day. If $1125$ handicraft items are to be displayed in an exhibition, then in how many days can $25$ children make these items?
Kiran spent $Rs. 6x$ on a book, $Rs. 6$ on food and had $Rs.18$ left. what was the sum of money she had at first? Express your answer in terms of $x$.
A person walks from his house at a speed of $4$ km/hr and reaches his schools $5$ minutes late. If his speed has been $5$ km/hr, he would have reached $10$ minutes earlier. The distance of the school from his house is
If $12$ men complete a work in $20$ days. If only $8$ men are employed, then the time required to complete the same work is
There are $50$ plates in a crate and there are $11$ such crates. When they are opened $\dfrac{2}{5}$ of the plates are found to be broken. How many plates are left intact?
Three friends, Mala, Leela and Sheela, divided a box of apples weighing $15\dfrac{9}{10}$ kg equally between the three of them. How many kgs of apples did each get?