If 3/p=4 & 3/q=18 then p-q=?	Choose the correct choice:
A) 5 / 24 B) 7 / 12 C) 7 / 24 D) 8 / 24 E) 9 / 24

Rationale: "p = 3 / 4 , q = 3 / 18 = > q = 1 / 6 therefore p - q = ( 3 / 4 ) - ( 1 / 6 ) = 7 / 12 answer : b"
Answer: B