Question

If $7,000 is placed in an account with an annual interest rate of 5.5%, how long will it take the amount to triple if the interest is compounded annually? Round your answer to two decimal places.

Answer 1

21,000 = 7000(1 + .055)^x
Now, solve, the answer is
20.52 Years.

Answer 2

\[A=P(1+(r/x))^nt\]Where:

A - Amount of money accumulated after n years, including interest
P - Principal amount (the initial amount you borrow or deposit)
r - annual rate of interest (as a decimal)
n - number of times the interest is compounded per year
t - number of years the amount is deposited or borrowed for

Just plug in the numbers given into the above formula, arrange it a little bit, and solve for t:
\[$21,000=$7,000(1+(0.055/1))^{1t}\]