What is the hidden question you need to answer before you can solve the problem ?

Iwill make brain if you me correctly fill this out needs due today pls and send it back to me (click the link and you will get it)

You deposit $5000 each year into an account earning 3% interest compounded annually. how much will you have in the account in 30 years?

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?