Please could you show the working out as well:)

The formula for the volume of a right square pyramid is given below, where a is the side length of the base and h is the height.

Astore is having a sale in which all items are reduced by 20 percent. including tax, jennifer paid $21 for a pair of shorts. if the sales tax is 5 percent, what was the original price of the shorts

What is the following sum in simplest form? square root 8 + 3 square root 2 + square root 32