Samuel invested money in his bank account. He had a principal, P, of $100 in his account at the beginning of the period, which increased at a rate, r, of 0.15 per year. At the end of the period, he had interest, I, of $105 in his account. Use the simple interest formula I = Prt, to solve for the time, t, in months that it took to earn this amount. (1 point) 7 months 58 months 84 months 700 months