At a restaurant, 25% of the dinner plates are clean. there are 80 total dinner
plates. how many dinner plates are clean?

How to do this , and can some one explain

Cody was 165cm tall on the first day of school this year, which was 10% taller than he was on the first day of school last year.

Which of the following are independent events? a) knowing that it is going to rain tomorrow, and bringing an umbrella to schoolb) knowing that you have to get up early tomorrow, and going to bed before 9 p.mc) knowing that it is going to rain tomorrow, and going to bed before 9 p.md) knowing that you have a test in school tomorrow, and studying thw night before