If 136 students represent 85% of those surveyed who said that math was their favorite class, then how many students didn't say math was their favorite?
A. 36
B. 15
C. 24
D. 30

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?