Investment problems such as those in Exercise can be solved by using a method similar to t...

Investment problems such as those in Exercise can be solved by using a method similar to the one explained in Example, along with the simple-interest formula I = PRT, where I is the interest earned, P is the initial amount of money deposited, R is the annual interest rate as a decimal, and T is the time the money is deposited in years. Solve each problem. Let T = 1 year for each exercise.

Example

Investing a Building Fund A church building fund has invested some money in two ways: part of the money at 4% interest and four times as much at 3.5%. Find the amount invested at each rate if the total annual income from interest is $3600.