Question

Tyler has two savings accounts that his grandparents opened for him. One of the accounts pay 10 % 10% annual interest, whereas the other pays 11 % 11% annual interest. If you have $ 700 $700 more invested at 11 % 11% than you invested at 10 % 10%, how much do you have invested in each account if the total amount of interest you earn in a year is $ 161 $161?

Answer 1

at 10% $ 400

at 11% $ 1,100

Step-by-step explanation:

principal x rate x time = interest

there is an account which yields at 10%another at 11% which also, is $700 dollar greater.

both yield 161 dollars

the equation would be:

`P_1 * 0.10 + P_2 * 0.11 = 161`

`P_1 * 0.10 + (P_1 + 700) * 0.11 = 161`

We can solve for the principal at 10%

`0.21P_1 + 77 = 161`

`0.21P_1 = 161 - 77`

`P_1 = 84/0.21 = 400`

Then first principal is for 400 dollars

the second: 400 + 700 = 1,100 dollars