Answer
a) $\dfrac{7}{13}$
b) $\dfrac{11}{13}$
Work Step by Step
Use the formula for a probability $P$ as: $\text{Probability}=\dfrac{\text{Number of favourable outcomes}}{\text{Number of all outcomes}}$
(a) Total people are: $4+9=13$ , out of which 4 are females (including ones under the age of 40) and 3 are under 40 males.
So, the probability of selecting a female or a male under age 40 is equal to $\dfrac{4+3}{13}=\dfrac{7}{13}$
(b) Total people are: $4+9=13$ , out of which 9 are males (including over the age of 40) and 2 are over 40 females.
So, the probability of selecting a male over age 40 is equal to $\dfrac{9+2}{13}=\dfrac{11}{13}$
