Bunuel
A certain account pays 1.5 percent compound interest every 3 months. A person invested an initial amount and did not invest any more money in the account after that. If after exactly 5 years, the amount of money in the account was T dollars, which of the following is an expression for the original number of dollars invested in the account?
A. \((1.015)^4T\)
B. \((1.015)^{15}T\)
C. \((1.015)^{20}T\)
D. \(\frac{T}{(1.015)^{15}}\)
E. \(\frac{T}{(1.015)^{20}}\)
Breaking Down the Info:\(1.5\%\) compound interest means we are multiplying the original amount by \(101.5\%\) every three months. After 5 years, we have 20 periods of 3-months, so the multiplying factor is \(1.015^{20}\).
Note that T is the resulting amount, however, so in order to find the principal we should divide by the factor above.
Answer: E