Keiko uses 8.1 pints of blue paint and white paint to paint her bedroom walls. 3
5
of this amount is blue paint, and the rest is white paint. How many pints of white paint did she use to paint her bedroom walls?

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?