Solve the problem.
-Find out how long it takes a $3300 investment to double if it is invested at 9% compounded monthly. Round to the nearest tenth of a year. Use the formula $$A = P \left( 1 + \frac { r } { n } \right) ^ { n t }$$ .
A)7.9 yr
B)7.5 yr
C)7.7 yr
D)8.1 yr

Question

Quizplus · Accepted Answer

To find the time it takes for the investment to double, use the formula $A = P \left( 1 + \frac { r } { n } \right) ^ { n t }$. Here, $A = 2P$, $r = 0.09$, $n = 12$. Solving for $t$, we get $t \approx 7.7$ years.

Solve the Problem A=P(1+rn)ntA = P \left( 1 + \frac { r } { n } \right) ^ { n t }A=P(1+nr​)nt

Solve the Problem $A = P \left( 1 + \frac { r } { n } \right) ^ { n t }$