What is the probability that a family of five children will

What is the probability that a family of five children will have at least three boys?

Solution

p=0.5, q=0.5, n=5

Probability of atleast three boys ina family of five= 5C3(0.5)³(0.5)²+5C4(0.5)⁴(0.5)¹+5C5(0.5)⁵(0.5)⁰=(0.5)⁵(10+5+1)=0.5