What is the final step in the problem solving

I'm being volume of cylinder with 13 in. radius and 30 in height answer choices in pic

Solve the equation.then check your solution 8=1.88+a

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