confusion in problem solving

[Gmatterz]

P,Q,R are positive integers such that Q is a factor of R and R is a multiple of P,which of the following must be an integer

a) (p+q)/r

b) (r+p)/q

c)p/q

d)pq/r

e)r(p+q)/pq

I am confused between choice b and e after substituting numbers at random.Please help

Thanks
Gmatterz

[stop@800]

You do not need random numbers at all

From 1
R/Q integer

from 2nd condition
R = nP [where n is any integer]
so
R/P is integer


R/Q and R/p are integers
so thr sum will also be integer

Add both

R/Q + R/p
R(p+q)/pq is integer
Ans E

[Gmatterz]

Thanks a lot for the above solution approach.