Rosie's Books prices its books by raising the wholesale price 40% and adding 50¢. What is the wholesale price of a book that sells for $39.95? Round to the nearest cent.

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?