Probability - help

gmatpup wrote:In a survey of 248 people, 156 are married, 70 self-employed, and 25% of those married are self-employed. If a person is to be randomly selected from those surveyed, what is the probability the person selected will be self-employed but not married?

A. 1/8
B. 4/31
C. 117/248
D. 1/4
E. 31/117

Answer is A

Thank you again

There are 156 married people, and "25% of those married are self-employed"
25% of 156 = 39
So, of the 156 married people, 39 are self-employed.

Now since there are 70 self-employed people in total, and since 39 of them are married, we know that 31 people are self-employed and not married (70-39=31).

So, out of 248 people, there are 31 people who are self-employed and not married.

So the probability that the selected person is self-employed but not married = 31/248 = 1/8 = A

Cheers,
Brent