Algebra help

Question

3,000 is deposited in an account that pays 5.9% interest compounded continuousl, how long does it need to stay in the account in order to double?

Answer 1

Amount = Principal (e)^(rate*time)

 

In general, A = Pe^rt

 

We know, P= 3,000

               r= 5.9%

               Amount = 6,000 (because we want to double our principal amount)

 

We want, t. 

 

rearranging our equation we get.

 

A=Pe^rt

 

A/P = e^rt

 

ln(A/P) = rt

 

[ln(A/P)] / r = t

 

plug in numbers.

 

[ln(6000/3000)] / 0.059 = t

 

t = 11.75 years

 

I hope this helps!