How to do this helppp ! i need this for my finals

If the simple annual interest rate on a loan is 6, what is the interest rate in percentage per month?

Find the equation of a line that is perpendicular to line g that contains (p, q). coordinate plane with line g that passes through the points negative 3 comma 6 and 0 comma 5 3x − y = 3p − q 3x + y = q − 3p x − y = p − q x + y = q − p

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?