Question

Herky and Elaina want to compare their investment accounts to see how much they will have in the accounts after eight years. They substitute their values shown below into the compound interest formula.

Compound Interest Accounts
Name
Principal
Interest Rate
Number of Years
Compounded
Herky
$500
5%
8
Once a year
Elaina
$400
6%
8
Once a year
mc013-1.jpg

Which pair of equations would correctly calculate their compound interests?
Herky: mc013-2.jpg, Elaina: mc013-3.jpg
Herky: mc013-4.jpg, Elaina: mc013-5.jpg
Herky: mc013-6.jpg, Elaina: mc013-7.jpg
Herky: mc013-8.jpg, Elaina: mc013-9.jpg

Answer 1

compound interest formula

P = A(1+r)^t
since they both compound once per year that makes the calculations pretty straightforward, plug Herky's numbers and Elaina's numbers into two instances of the equation and see which choice matches the result