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 $280 in interest. What were the interest rates of the money market account and the stock?
Answer provided by our tutors
Money market interest = x
stock interest = 3x
2000x + 2000 (3x) = 280
8000x = 280
x = 0.035 = 3.5%
stock interest = 3.5 * 3 = 10.5%