I need an algebraic equation, with all work shown.

Question

My example is, I need to know at what point the compound interest doubles. What I know is, 1st year accrued interest is $1.36 trillion dollar, interest rate is 8% and principle amount is $17 triillion. Can anyone help??

Answer 1

it must not be compounding continuously, and the difficulty comes from not knowing the frequency of compounds per year.

 

Use the formula F=P(1+r/n)^{nt}

 

We are given information about a time period of 1 year, and asked to find the time period it takes for F=2P.

Thus

P+(interest for 1 year) = P(1+r/n)^n...writing the following should help you see the solution!

 

2P = P[(1+r/n)^n]^t