Hi there, can anyone solve this one (it feels like a standard question but I get stuck):
Q: In a survey of 248 people, 156 are married, 70 are self-employed and 25% of those married are self-employed. If a person is randomly selected from those surveyed, what is the probability that 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
I ended up guessing e). Correct answer is a).
Many thanks in advance.