How long will it take for the value of an account to be $890 if $350 is deposited at 11% interest compounded continously?

Thanks!! ;)

Question

How long will it take for the value of an account to be $890 if $350 is deposited at 11% interest compounded continously? 

Thanks!! ;)

anonymous · Answer

Use the rule of 72. 72/ 11 = 6.5. 890 is 2.5 times 350 so with the answers you have it would be 8.48 yrs.

anonymous · Answer

8.48 is the answer

mathstudent55 · Answer

A = pe^(rt)
where p = principal amount (what you start with)
e = base of natural log
r = interest rate (as a decimal: 5% = 0.05)
t = time (number of years)
A = amount at end of t years at r interest

anonymous · Answer

@blast234 , yes it is the answer.

anonymous · Answer

Welcome

anonymous · Answer

But I would like to understand it better, in this case what will be the time...???

anonymous · Answer

Oh, then its Ok.

anonymous · Answer

Mathstudent was also helpful XD

anonymous · Answer

he deserves a medal too

mathstudent55 · Answer

A = pe^(rt)
890 = 350e^(0.11t)
e^(0.11t) = 890/350 = 89/35
ln(e^(0.11t)) = ln (89/35)
0.11t = ln (89/35)
t = (ln (89/35))/0.11

anonymous · Answer

Thank you so much!!! You deserved it =D

mathstudent55 · Answer

wlcm