In a certain class, one student is to be selected at random to read. what is the probability that a boy will read?
1. Two-thirds of the students in the class are boys.
2. Ten of the students in the class are girls.
since 2/3 of the students are boys, the prob of that a boy selected is 2/3.
We know the number of girls. But we do not know the number of boys.
Let the number of boys is 20 then the answer will be 2/3.
And let the number of boys is 30 then the answer will be 3/4.