Question

Oliver's grandfather invested $150 at 5% interest compounded quarterly. When Oliver inherited it, the amount was $6000. For how many years had the $150 been invested?

Answer 1

\[A=P(1+\frac{r}{n})^{nt}\]
where A is the amount after t years
P is the principal amount
r is the interest rate
n is the number of compounding periods in a year.