40.50 dived by 18 long division

The jewelry store is having a sale. necklaces that were regularly priced at $23.50 are on sale for $18.80. what is the percentage of decrease in the price of necklaces?

The figures below are made out of circles, semicircles, quarter circles, and a square. find the area and the perimeter of each figure and give your answers as a completely simplified exact value in terms of π (no approximations).

What effect would doubling all the dimensions of a triangular pyramid have on the volume of the pyramid? explain your reasoning.