I need help with questions b-d

With this question! what is process of elimination? ? p.s. my brothers acc got banned so add his new one @ yamauchiyamyam17

Aswimming pool is a rectangle with semicircles on the end. the rectangle is 12 meters wide and 30 meters long. the diameter and width of the swimming pool are equal. sketch and label an overhead diagram of the swimming pool. find the area of the swimming pool floor.

Bernice paid $162 in interest on a loan of $1800 borrowed at 6%. how long did it take her to pay the loan off?