Page 64 - Maths Class 05

c. 32, 40 and 52 : i. ____________________________________

ii. ____________________________________

iii. ____________________________________

iv. ____________________________________

v. ____________________________________

3. Find the LCM of the following numbers (use any convenient method you like).

a. 12, 16 and 20 b. 50 and 150 c. 36 and 60

d. 110, 120 and 440 e. 250 and 300 f. 180, 225 and 375

g. 512, 256 and 128 h. 425 and 675 i. 144, 288 and 108

4. Find all the common factors of the given numbers in each group.

a. 24 and 40 b. 9 and 24 c. 12 and 21

d. 12, 16 and 30 e. 17, 27 and 39 f. 24, 40 and 50

5. Draw a factor tree to find the prime factors of each of the following numbers.

a. 21 b. 140 c. 72

d. 90 e. 26 f. 45

6. Express each of these numbers as a product of its prime factors.

a. 12 b. 28 c. 50

d. 72 e. 112 f. 90

7. Find the highest common factor for these groups of numbers.

a. 4, 6 b. 6, 12 c. 9, 12, 24

d. 14, 21, 49 e. 12, 18, 24 f. 16, 32, 48

8. Find the lowest common multiple for these groups of numbers.

a. 3, 4 b. 4, 9 c. 10, 15

d. 4, 5, 9 e. 5, 8, 16 f. 6, 12, 18

9. Jack thinks of two numbers, the HCF of these numbers is 6 and LCM is 72. If one of the

numbers is 24, suggest what his other number may have been.

10. The lowest common multiple of two numbers is 36 and highest common factor is 3. If one

of the numbers is 12, suggest what the other number might be.

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