Ernie deposited $4000 between two savings accounts. One account paid 4% simple interest and the other paid 2%. At the end of one year, Ernie had earned $140 in interest for both accounts. How much money did Ernie deposit in the account that paid 4% interest?
Accepted Solution
A:
Let x represent the amount of $ in the 4% account and y in the 2% account. Then x + y = $4000 (total savings).
Interest at 4% would be x*0.04*1 = 0.04x, and Interest at 2% would be y*0.02*1 = 0.02y.
Then 0.04x + 0.02y = $140 interest, total.
We must solve this system of linear equations.
Mult. 0.04x + 0.02y = $140 by 100 to remove the fractions:
4x + 2y = $14000 We already know that x + y = $4000, so y = $4000-x.