SOLUTION: 15. There are 20 children in the cast of a class play, and 8 of the children are boys. Of the boys, 4 have a speaking part in the play, and of the girls, 8 do not have a speaking

Question 939002: 15. There are 20 children in the cast of a class play, and 8 of the
children are boys. Of the boys, 4 have a speaking part in the
play, and of the girls, 8 do not have a speaking part in the
play. If a child from the cast of the play is chosen at random,
what is the probability that the child has a speaking part?
Answer by mathmate(429) (Show Source): You can put this solution on YOUR website!

It all looks confusing when we try to juggle with all those numbers in the head. The problem can be solved systematically by constructing a contingency table.

role/gender B G total
speaking...... 4 4 8
silent............ 4 8 12
total............. 8 12 20
Probability of a child having a speaking part is therefore
RELATED QUESTIONS
There are 20 children in the cast of a class play, and 8 of the children are boys. Of the (answered by richwmiller)

There are 20 children in the cast of a class play, and 8 of the children are boys. Of... (answered by greenestamps)

In a class 18 children are girls and 25% of the class are boys. How many children are... (answered by JoelSchwartz)

In a class of c children, there are 16 boys. what fraction of the class are boys. (answered by solver91311)

There are 72 children in a school. 5/8 of the children are boys. How many boys are... (answered by Alan3354)

� of a class are girls. 5 class members are boys. How many children are there in the... (answered by richwmiller,harpazo)

There are 20 children in a class, and 12 of the children are girls. Of the girls, 8... (answered by jim_thompson5910,ikleyn)

if there are 18 girls in a class, and a quarter of the class are boys, how many children... (answered by Cromlix)

A teacher has 20 boys and 10 girls in her class. In how many way can she select 6 of the (answered by ikleyn)