Question

Find the probability that when a couple has six ​children, at least one of them is a girl. ​(Assume that boys and girls are equally​ likely.)

Answer 1

Answer:

Pr(at least a girl) = $\frac{7}{8}$          

Step-by-step explanation:

Probability = Number of required outcomes / number of possible outcomes

We are to find the probability of at least one girl. assuming the likelihood of boys and girls are equal.

Pr( boy) = $\frac{1}{2} =0.5$

Pr (three boys) = Pr(boy) * Pr(boy)  *Pr (boy)

                         =0.5*0.5*0.5

                         =0.125

Pr ( at least a girl) = Pr (not getting a boy)

Pr(at least a girl) = 1- Pr(three boys)

Pr(at least a girl) = 1-0.125

Pr(at least a girl) = 0.875

Pr(at least a girl) = $\frac{7}{8}$