The perimeter of this shape is 120 π mm

What is the radius of the smaller semicircles?

Cam bought some used books for $4.95. he paid $0.50 each for some books and $0.35 each for the others. he bought fewer than 8 books at each price. how many books did cam buy?

Ageologist had two rocks on a scale that weighed 4.6 kilograms together. rock a was 0.5 of the total weight. how much did rock a weigh?

There is an entrance to the computer room at point e which lies on ab and is 5 feet from point a. plot point e on the coordinate plane. find the distance from the entrance at point e to the printer at point e