1.  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?
A. 10
B. 20
C. 40
D. 60

Answer: Option D

Explanation:

Let x and y be the number of deer and peacocks in the zoo respectively.
Then, x + y = 80 ------------------> (i)
4x + 2y = 200 or 2x + y = 100 ---------> (ii)
Solving (i) and (ii), we get : x = 20, y = 60.