There are deer and peacocks in a zoo. By counting heads they are 80. The number of their legs is 200. How many peacocks are there ?
Choose the correct choice from the following
A) 20
B) 30
C) 50
D) 60
E) 80
Explanation:   Let x and y be the number of deer and peacocks in the zoo respectively. Then,   x + y = 80 ...(i) and   4x + 2y = 200 or 2x + y = 100 ...(ii)   Solving (i) and (ii), we get) x = 20, y = 60.   Answer: 60
<result>D</result>
There are deer and peacocks in a zoo. By counting heads they are 80. The number of their legs is 200. How many peacocks are there ?