Explanation
Correct answer: B.
Choice B is correct. There were days with no rain. It was a weekend day for of those days. So out of of the days with no rain were weekend days. Because the day is selected at random, each day has an equal chance of being selected, so the probability is .
Desmos solution:
Note: Given no rain, divide the 16 weekend days with no rain by all 64 days with no rain.
Enter in Desmos:
Reviewed and rewritten by CookSAT
Why the other choices are wrong
Choice A
Choice A is incorrect. It is the probability that a day selected at random from any one of the days during the weeks is a weekend day with no rain.
Choice C
Choice C is incorrect. It is the probability that a day selected at random from the weekend days has no rain.
Choice D
Choice D is incorrect. It is the probability that a day selected at random from the days with no rain is a weekday.