Pls help I hate math rectangular prism

What is the area of triangle abc if a = 8, b = 11, and c = 15?

Determine the volume of a cylinder bucket if the diameter is 8.5 in. and the height is 11.5 in.

The administrator of a large assisted living facility wanted to know the average age of the residents living at the facility. he randomly selected 12 residents and determined their age, listed here: 80, 65, 75, 83, 68, 73, 88, 79, 94, 72, 79, 68 what's the average age of the sample of residents? a. 79 years old b. 68 years old c. 75 years old d. 77 years old