Problema Solution

A high school student was able to save $4000 by working a part-time job every summer. He invested half the money in a money market account and half the money in a stock that paid three times as much interest as the money market account. After a year he earned $200 in interest. What were the interest rates of the money market account and the stock?

Answer provided by our tutors

interest + interest = interest

r*2000 + 3r*2000 = 200 dollars

8000r = 200

r = 0.025= 2.5%

3r = 3*0.025

3r =0.075

=7.05%