Question

EXERCISE 3.4
Find the common factors of
(a) 20 and 28 (b) 15 and 25 C) 35 and 50 56 and 120
Find the common factors of
(a) 4, 8 and 12 (b) 5,15 and 25
Find first three common multiples of :
(a) 6 and 8 (b) 12 and 18
Write all the numbers less than 100 which are common multiples of 3 and 4
Which of the following numbers are co-prime?
(a) 18 and 35 (6) 15 and 37 (c) 30 and 415
(d) 17 and 68 (e) 216 and 215. (f) 81 and 16
A number is divisible by both 5 and 12. By which other number will that number be
always divisible?
A number is divisible by 12. By what other numbers will that number be divisible?​

Answer 1

Answer:

(a)1,2,4

(b)1,5

(c)1,5

(d)1,2,4,8

(a)1,2,4

(b)1,5

6.if a number is 5 and 12 the no. will be divisible by 5x12=60

7.factors of 12= 1,2,3,4,6 and 1

therefore, if the no. is divisible by 12 it is divisible by 1,2,3,4,6 and 12