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

Retirement Planning In planning her retirement, Mary Lynn Ellis deposits some money at 2.5% interest with twice as much deposited at 3%. Find the amount deposited at each rate if the total annual interest income is $850.