balance in an account after t years is given by
A = Pert,
where P is the initial investment and r is the interest rate.

1.How long will it take for $2000 to double if it is invested at 13% interest compounded continuously?

2. What rate of interest compounded continuously is needed for an investment of $500 to grow to $900 in 10 years?

Question

balance in an account after t years is given by 
A = Pert,
where P is the initial investment and r is the interest rate.

1.How long will it take for $2000 to double if it is invested at 13% interest compounded continuously?

2.  What rate of interest compounded continuously is needed for an investment of $500 to grow to $900 in 10 years?

amistre64 · Answer

anonymous · Answer

13% compounded continuously?  wishful thinking!
solve $$2=e^{.13t}$$ for t to get 
$$.13t=\ln(2)$$
$$t=\frac{\ln(2)}{.13}$$
then a calculator

anonymous · Answer

how do i calculate that?

amistre64 · Answer

type:  ln(2)/.13 into google and it calculates it