1.  What is the smallest number of ducks that could swim in this formation - two ducks in front of a duck, two ducks behind a duck and a duck between two ducks ?
A. 3
B. 5
C. 7
D. 9

Answer: Option A

Explanation:

Clearly, the smallest such number is 3.

Three ducks can be arranged as shown above to satisfy all the three given conditions.