Question 140090
the formula you need is A=Pe^(rt)
__ A is the Amount after time t
__ P is the Principal you start with
__ e is Euler's number (the base for natural logarithms)
__ r is the rate of interest
__ r and t have to use the same time units


100000=50000e^(.04t) __ dividing by 50000 __ 2=e^(.04t)


taking natural log __ ln(2)=.04t __ dividing by .04 __ [ln(2)]/.04=t