In a group of ducks and cows, the total number of legs are 30 more than twice the no. of heads. Find the total no.of buffaloes.  Choose the correct choice from the following answers.
A) 11	B) 12	C) 14	D) 15	E) 18

Rationale: "let the number of buffaloes be x and the number of ducks be y = > 4 x + 2 y = 2 ( x + y ) + 30 = > 2 x = 30 = > x = 15 d"
Answer: D