In a group of ducks and cows, the total number of legs are 36 more than twice the no. of heads. Find the total no.of buffaloes. Choose one
A) 10  B) 12  C) 13  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 ) + 36 = > 2 x = 36 = > x = 18 e"
Answer: E