The cost that a carpet cleaning company charges is directly proportional to the number of rooms cleaned. The cost to clean 50 rooms is $1,100.
A.) Write a direct variation equation to represent the cost. (1 pt.)
B.) Using the equation found in part a, how much would it cost a hotel to have 150 rooms cleaned? (1 pt.)

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?

Which will form a composite function?

Bob paid $3 less than tim at a local pizza parlor. together they spent $7.80. how much did bob pay for pizza?