Question

Liam deposited $1,724.53 in a savings account 4 months ago. The account earns 3.1% simple interest. What is his account balance today?

Answer 1

is the interest rate... 3.1% per month.. or per annum..?

Answer 2

Assuming it is a monthly interest rate, he would earn 3.1% more money from the base value each month. For one month it's just $1724.53 * 0.031 = $53.46. Now all you have to do is multiply that by 4 months, because he will be getting that extra $53.46 every month. You end up with $1938.37.