Diva wants to make a flower arrangement for her aunt's birthday. She purchases 12 roses. She wants 1/3 of the flowers in the arrangement to be roses. How many more flowers must she buy?

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?