Question

If an integer m is divisible by both 10 and 12, then it must also be divisible by which of the following?

(A) 20
(B) 22
(C) 24
(D) 26
(E) 28

Answer 1

20

Explanation:

an integer m is divisible by both 10 and 12

Lets write the prime factor for each number

the prime factor for 10 is 5,2

the prime factor for 12 is 3,2,2

Now take the product of the prime factors that are not in common and also in common
`5 \cdot 3 \cdot 2 \fdot 2= 60`

60 is divisible by 20

so answer is 20