
Mauricio M. answered 07/13/22
Credentialed Secondary Math Teacher
Let x represent the amount invested at 12%. Since Jolene puts twice as much in the lower yielding account, it follows that, 2x is the amount invested at 5%. The total annual interest earned is the sum of the annual interest earned in both accounts.
Total Annual Interest = Annual Interest Earned at 12% + Annual Interest Earned at 5%
Since simple interest per year is given by amount invested times annual interest rate, we write and solve the following equation:
5412 = 0.12(x) + 0.05(2x)
5412 = 0.12x + 0.10x
5412 = 0.22x
x = 5412 ÷ 0.22
x = 24600 ⇒ 2x = 49200
So that:
The amount invested at 5% interest is $49,200.
The amount invested at 12% interest is $24,600.