A certain amount of money is invested in the bank with an annual interest rate of 15% for 4 years.

A certain amount of money is invested in the bank with an annual interest rate of 15% for 4 years. If the amount deposited in the bank is $ 120 more than the accumulated interest increase, how many dollars will be the interest income received from the bank?

Let’s denote by x the amount of money invested in the bank.

In the condition of the problem it is said that the annual interest rate is 15%, therefore, in 4 years the amount of money in the bank will be:

x + 4 * (15/100) * x = x + (60/100) * x = x + (6/10) * x = x + 0.6 * x = 1.6x.

According to the condition of the problem, the amount invested in the bank is $ 120 more than the accumulated percentage increase, therefore, we can draw up the following equation:

x = 120 + 1.6x – x.

We solve the resulting equation:

x = 120 + 0.6x;

x – 0.6x = 120;

0.4x = 120;

x = 120 / 0.4;

x = 300.

Then the interest income received from the bank is:

300 – 120 = $ 180.

Answer: The interest earned from the bank is $ 180.