Question

Holly P. has invested her latest paycheque of $500 in two accounts. One earns 5% interest a year the other 7.5% interest a year. After 3 years she has made $100.50 in interest. How much
did she invest into each account?

Answer 1

Let's assume Holly invested x dollars in the first account that earns 5% interest and (500-x) dollars in the second account that earns 7.5% interest.

The interest made from the first account after 3 years is x * 0.05 * 3 = 0.15x

The interest made from the second account after 3 years is (500-x) * 0.075 * 3 = 0.225(500-x)

The total interest made is 0.15x + 0.225(500-x) = 100.50

Expanding and solving for x, we get:

0.15x + 112.5 - 0.225x = 100.50

-0.075x = -12

x = 160

So, Holly invested $160 in the first account and $340 in the second account.