<PRE><B>Question 400831</B>
A high school student was able to save $3000 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.
---
1500 invested at r
1500 invested at 3r
-------

After a year he earned $90 in interest. 
What were the interest rates of the money market account and the stock? 
Answer in percentages and round to one decimal place.
----
Equation:
interest + interest = interest
1500r + 1500(3r) = 90
1500r + 4500r = 90
6000r = 90
r = 0.015 or 1.5% (money market investment rate)
3r = 0.045 or 4.5% (stock investment rate)
============================
cheers,
stan H.</PRE>