How many randomly assembled people are needed to have a better than 50% probability that at least 1 of them was born in a leap year?

A. 1

B. 2

C. 3

D. 4

E. 5

For detailed Answers..

Probability of a randomly selected person NOT to be born in a leap year=3/4

Among 2 people, probability that none of them was born in a leap = 3/4*3/4=9/16. The probability at least one born in leap = 1- 9/16=7/16<1/2

So, we are looking for such n (# of people), when 1-(3/4)^n>1/2

n=3 --> 1-27/64=37/64>1/2

Thus min 3 people are needed.

Answer: C.