The formula is A=pe^rt A future value 250 P present value 100 E constant R interest rate 0.09 T time? 250=100e^0.09t Solve for t 250/100=e^0.09t Take the log Log (250/100)=log (e)×0.09t 0.09t=log (250/100)÷log (e) T=(log(250÷100)÷log(e))÷0.09 T=10.18 years round your answer to get 10 years
