2m-3 and 10m-15 are coprime integers.Which of the choices from below

is coprime with each one of the numbers?

a)3m-1

b)m+4

c)2m+6

d)m+3

e)5m

Answer is b.

I couldn't find the answer.

First of all both numbers are not coprime. When we divide them with

each other we get 5 or 1/5.