### Home > CC3 > Chapter 9 > Lesson 9.1.3 > Problem 9-37

9-37.

Joaquin has agreed to lend his younger brother

Joaquin is charging his brother

simple interest per month. If his brother pays him back in 6 months, how much will Joaquin get back? Using the equation for simple interest:

Remember, the total money Joaquin gets back includes the principal and the interest.

If Joaquin’s brother instead borrowed the money from a bank at

compound interest per month, how much would he have to pay the bank at the end of 6 months? Use the equation for compound interest: