Answer: There is a probability that a club member picked randomly is female, given that the person prefers swimming on weekends is 40%.
Step-by-step explanation:
Let E₁ be the event that members prefer swimming on weekends.
Let E₂ be the event that members prefer swimming on weekdays.
Let A be the event that the members are female.
Probability that members prefer swimming on weekends P(E₁) = 25%
Probability that members prefer swimming on weekdays P(E₂)= 75%
Probability that members prefer swimming on weekends and are female PA∩E₁)= 10%
Probability that members prefer swimming on weekdays and are female P(A∩E₂) = 55%
Using Conditional theorem, we will find the probability that a member is female given that the the person prefers swimming on weekends.

Hence, there is a probability that a club member picked randomly is female, given that the person prefers swimming on weekends is 40%.