Question

A couple has three children. Find each probability:

 a . All boys

 b. All girls or all boys

 c. Exactly two boys or two girls

d. At least one child of each gender gril.

 

Answer 1

Order is not important

$$BBB, BBG, BGG, GGG$$

a.

$$P(BBB)=\dfrac{1}{4}=0.25$$

b.

$$P(BBB\ or \ GGG)=\dfrac{2}{4}=\dfrac{1}{2}=0.5$$

c.

$$P(BBG\ or\ BGG)=\dfrac{2}{4}=\dfrac{1}{2}=0.5$$

d.

$$P(at\ least\ 1 \ of \ each\ gender)=\dfrac{2}{4}=\dfrac{1}{2}=0.5$$