### Home > MC2 > Chapter 9 > Lesson 9.1.2 > Problem9-21

9-21.

Joaquin has agreed to lend his younger brother $45 so that he can buy a new tank for his pet lizard. Joaquin is charging his brother 2% simple interest per month. If his brother pays him back in 6 months, how much will Joaquin get back? Homework Help ✎ Using the equation for simple interest: Interest = Prt P = principal r = interest rate t = time Interest =$45(.02)(6 months)

\$50.40

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