Monica deposits ​$400 into a savings account that has a simple interest rate of 4.1​%

I wonder when she found such a high interest rate.

I recall such rates in about 1964, but it was, of course, compound interest.

To calculate the simple interest gained on Monica's deposit, follow these steps:

Step 1: Convert the percentage interest rate into a decimal form. In this case, 4.1% becomes 0.041 (divide by 100).

Step 2: Multiply the deposit amount by the decimal interest rate to calculate the interest gained.

Interest = Deposit Amount * Decimal Interest Rate
Interest = $400 * 0.041
Interest = $16.40

Therefore, Monica would earn $16.40 in interest on her $400 deposit.