Question

Larry borrows $1300 at 5% simple interest per month. When

Larry pays the loan back 3 years later, what is the total amount that Larry ends up repaying?

1300x0.05x3=195

Answer 1

Nope. Read the question carefully. It's 5% per month, not per year.

In the formula i = Prt
t is the number of interest periods.

also, you calculated only the interest. Larrya has to pay the interest plus the original principal.
A = P(1 + rt)