You pay 3.5% annual simple interest for 12 years on a loan, and you pay $1,512 in interest. How much is the principal?

A = Pe^rt
Amount of interest paid = Principal*e^ (rate*time)
(The rate must be in decimal form)
3.15% / 100 = .0315

1,512 = P[e^(.0315*12)]
1,512 / e^(.0315*12) = P
1036.06 = P
$1036.06 was the Principal
** I left that value unrounded to the hundreds place because one doesn’t round with money. :)

Good luck!