Mason took out an $800 loan from the bank. At the end of 5 years, he pays back the principal, plus $120 simple interest. What was the interest rate? PLZ HELP ME

Simple interest=principal×rate×time
I=prt

Simple interest=120
Time=5
Principal=800

120=(800)(5)r
120=4000r
120/4000=4000/4000r
3/100=r
3%=r

Rate=3%