(a) Given that x = {whole numbers from 4 to 13} and y = {multiples of 3 between 2 and 20},
find X ∩ Y .

(b) Find the Least Common Multiple (L.C.M) of the following numbers: 3, 5, and 9.

(c) If ${p+2q}/{p}={7}/{5}$, find the value of q/p, where p &neq; 0.