• Playing With Numbers - 23
Back
0

Playing With Numbers - 23

Description: Playing with Numbers - 23
Number of Questions: 25
Created by:
Tags: Playing with Numbers - 23 Playing with Numbers L.C.M. and H.C.F. Reasoning
Start the Quiz
Attempted 0/25 Correct 0 Score 0
‹
›

What is the result obtained when greatest common factor of 64 and 80 takes away 11?

  1. 5

  2. 9

  3. 7

  4. 11

Show answer
Correct Option: A
Explanation:

Factors of 64 are 1, 2, 4, 8, 16, 32, 64. Factors of 80 are 1, 2, 4 5, 8, 10, 16, 20, 40, 80. Greatest common factor of 64 and 80 is 16. Result obtained = 16 - 11 = 5

What is the result obtained when greatest common factor of 36 and 30 added to the greatest common factor of 28 and 35?

  1. 11

  2. 12

  3. 13

  4. 17

Show answer
Correct Option: C
Explanation:

Greatest common factor of 36 and 30 is 6. Factors of 28 are 1, 2, 4, 7, 14, 28. Factors of 35 are 1, 5, 7, 35. G.C.F of 28 and 35 is 7. Result obtained = 6 + 7 = 13

Jessica has clothes of different lengths measuring 240 cm, 318 cm and 426 cm. What is the largest possible length of each piece that are to be cut so that they are equal in length without anything remaining?

  1. 8 cm

  2. 7 cm

  3. 6 cm

  4. 5 cm

Show answer
Correct Option: C
Explanation:

HCF of 240, 318 and 426 is 6. So, the length of each part will be 6 cm.

Which of the following options is the greatest common factor of 84 and 35?

  1. 16

  2. 8

  3. 7

  4. 2

Show answer
Correct Option: C
Explanation:

Factors of 80 are 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42 and 84. Factors of 35 are 1, 5, 7, 35. Greatest common factor is 7.

Find the highest common factor of 56 and 72.

  1. 5

  2. 6

  3. 7

  4. 8

Show answer
Correct Option: D
Explanation:

The HCF of 56 and 72 is 8.

John has prepared such a toy that rings first bell after every 8 minutes, second bell rings after every 10 minutes and the third bell rings after every 15 minutes. If all the bells have rung together at 8 : 30 AM, when will they ring together again?

  1. 10 : 15 AM

  2. 10 : 30 AM

  3. 10 : 35 AM

  4. 10 : 45 AM

Show answer
Correct Option: B
Explanation:

The LCM of 15, 10, 8 is 120 So, the 3 bells will ring together after 120 minutes. i.e., 2 hours i.e., at 10 : 30 AM

Find the LCM of 18 and 24?

  1. 24

  2. 36

  3. 48

  4. 72

Show answer
Correct Option: D
Explanation:

Multiples of 18 are 18, 36, 54, 72, 90. Multiples of 24 are 24, 48, 72, 96. So, 72 is the LCM of 18 and 24.

In a school canteen, pie is served every fourth day and pudding is served every seventh day. If they both are served today, on which day they will be served together?

  1. 25th

  2. 26th

  3. 27th

  4. 28th

Show answer
Correct Option: D
Explanation:

LCM of 4 and 7 = 28 So, both pie and pudding will be served on the 28th day.

Find the HCF of 36, 54 and 45.

  1. 8

  2. 9

  3. 10

  4. 11

Show answer
Correct Option: B
Explanation:

Factors of 36 are 1, 2, 4, 6, 9, 12, 18, and 36. Factors of 54 are 1, 2, 3, 6, 9, 18, 27, and 54. Factors of 45 are 1, 3, 5, 9, 15, and 45. So, 9 is the HCF.

Find the LCM of 9 and 12.

  1. 27

  2. 36

  3. 48

  4. 108

Show answer
Correct Option: B
Explanation:

LCM of 9 and 12  Multiples of 9 are 9, 18, 27, 36, 45, 54. Multiples of 12 are 12, 24, 36, 48. 36 is the LCM.

Cookies and milk are served daily in the kindergarden class to students before their nap time. But every fifth day and ninth day, juice and hot chocolate is served respectively. If both are served together today, on which day juice and hot chocolate both will be served together again?

  1. 30

  2. 35

  3. 40

  4. 45

Show answer
Correct Option: D
Explanation:

LCM of 5 and 9: Multiples of 5 are 5, 10, 15, 20, 25, 30, 35, 40, 45, 50. Multiples of 9 are 9, 18, 27, 36, 45, 54. So, every 45th day they will be served together from today.

What is the greatest common factor of 84 and 56?

  1. 14

  2. 28

  3. 29

  4. 32

Show answer
Correct Option: B
Explanation:

Greatest common factor of 84 and 56 is 28. Factors of 84 are 1, 2, 3, 4, 6, 7, 12, 14, 21, 28 and 42. Factors of 28 are 1, 2, 4, 7, 14, 28. So, greatest number which is common is 28.

Jim visits his Edinburgh office every second month and his Yorkshire office every third month. If he visited both his offices in this month, when will he visit both the offices in the same month again?

  1. 4th month

  2. 5th month

  3. 6th month

  4. 7th month

Show answer
Correct Option: C
Explanation:

LCM of 2 and 3 is 6. So, he visits both his offices together in the 6th month.

What is the fourth multiple of the greatest common factor of 6 and 18?

  1. 24

  2. 28

  3. 30

  4. 36

Show answer
Correct Option: A
Explanation:

Factors of 6 = 1, 2, 3, 6 Factors of 18 = 1, 2, 3, 6, 9, 18 Greatest common factor = 6 6 × 4 = 24

What is the sum of the first four multiples of the least common multiple of 3 and 8?

  1. 260

  2. 256

  3. 240

  4. 220

Show answer
Correct Option: C
Explanation:

Multiples of 3 = 3, 6, 9, 12, 15, 18, 21, 24 Multiples of 8 = 8, 16, 24 Least common multiple = 24 24 × 1 = 24, 24 × 2 = 48, 24 × 3 = 72, 24 × 4 = 96 24 + 48 + 72 + 96 = 240

Three numbers are in the ratio 1 : 2 : 4 and their LCM is 280. Find their HCF.

  1. 15

  2. 30

  3. 45

  4. 40

Show answer
Correct Option: D
Explanation:

The ratio of three numbers is 1:2:4 1x, 2x, 4x and LCM = 280 1 x + 2 x + 4x = 280  7x = 280 x = 40 HCF = 40

Which of the following options is the greatest common factor of 64 and 80?

  1. 10

  2. 14

  3. 16

  4. 22

Show answer
Correct Option: C
Explanation:

Factors of 64 are 1, 2, 4, 8, 16, 32, 64. Factors of 80 are 1, 2, 4, 5, 8, 10, 16, 20, 40, 80. Greatest common factor is 16.

How many factors does the greatest common factor of 15 and 20 have?

  1. 2

  2. 4

  3. 6

  4. 8

Show answer
Correct Option: A
Explanation:

Factors of 15 = 1, 3, 5, 15 Factors of 20 = 1, 2, 4, 5, 10, 20 Greatest common factor = 5 Factors of 5 are = 1 and 5 So, factors of 5 are 2 in numbers.

What is the least number which when doubled will be exactly divisible by 14, 21, 30?

  1. 105

  2. 120

  3. 150

  4. 180

Show answer
Correct Option: A
Explanation:

 LCM of 14, 21 and 30 14 = 2 x 7 21 = 3 x 7 30 = 2 x 3 x 5

LCM = 2 x 3 x 5  x 7 = 210 Half of  210 = 105

What is the greatest common factor?

  1. The smallest of the large factors

  2. The largest of the common factors

  3. The sum of the common factors

  4. The first multiple of the largest factor

Show answer
Correct Option: B
Explanation:

The largest of the common factors

Which of the following options are the two common multiples of 8 and 12?

  1. 12 and 24

  2. 24 and 32

  3. 24 and 48

  4. 24 and 36

Show answer
Correct Option: C
Explanation:

Multiples of 8 = 8, 16, 24, 32, 40, 48 Multiples of 12 = 12, 24, 36, 48 Common multiples = 24, 48

What is the lowest common multiple of 7 and 9?

  1. 63

  2. 56

  3. 49

  4. 35

Show answer
Correct Option: A
Explanation:

Multiples of 7 = 7, 14, 21, 28, 35, 42, 49, 56, 63 Multiples of 9 = 9, 18, 27, 36, 45, 54, 63 Least common multiple = 63

What is the fourth multiple of the greatest common factor of 84 and 56?

  1. 96

  2. 102

  3. 108

  4. 112

Show answer
Correct Option: D
Explanation:

Factors of 84 = 1, 2, 3, 4, 6, 7, 12, 14, 21, 28, 42, 84
Factors of 56 = 1, 2, 4, 7, 8, 14, 28, 56 Greatest common factor = 28 28 × 4 = 112

What is the greatest common factor of 21 and 35?

  1. 1

  2. 3

  3. 5

  4. 7

Show answer
Correct Option: D
Explanation:

Factors of 21 = 1, 3, 7, 21 Factors of 35 = 1, 5, 7, 35 Greatest common factor = 7

Given that the lowest common multiple of 9 and 5 is added to the greatest common factor of 77 and 33. It gives us the number x. What is the 3rd multiple of x?

  1. 178

  2. 168

  3. 158

  4. 148

Show answer
Correct Option: B
Explanation:

Multiples of 9 = 9, 18, 27, 36, 45 Multiples of 5 = 5, 10, 15, 20, 25, 30, 35, 40, 45 Least common multiple = 45 Factors of 77 = 1, 7, 11, 77 Factors of 33 = 1, 3, 11, 33 Greatest common factor = 11 11 + 45 = 56 56 × 3 = 168

- Hide questions
ADVERTISEMENT

Find more quizzes from top tags

general knowledge
3615 Quizzes
119858 Questions
 technology
307 Quizzes
36705 Questions
 sports
963 Quizzes
19148 Questions
 history
1187 Quizzes
13475 Questions
 physics
598 Quizzes
13441 Questions
 biology
1160 Quizzes
12174 Questions
 science & technology
551 Quizzes
11015 Questions
 chemistry
490 Quizzes
9892 Questions
 maths
518 Quizzes
9324 Questions
 softskills
0 Quizzes
7131 Questions