Question

WILL GIVE MEDAL

The amount of money in the bank can be expressed by the exponential equation
A = 300 (1.005)^12t
Where A is the amount in dollars and t is the time in years. About how many years will it take for the amount in the account to be more than $900?

A. 18 years
B. 30 years
C. 220 years
D. 37 years

Answer 1

A=300(1.005)^12t > 900
1.005^12t>900/300
1.005^12t>3
ln(1.005^12t)>ln3
12t ln1.005>ln3
12t>(ln3)/(ln1.005)
t>(1/12)(ln3)/(ln1.005)
t>18.4

It will take about 18 years for the amount in the account to be more than $900. So your answer is A :)

Answer 2

Thank you so much!

Answer 3

No problem! :)