Maths

Apply the formulae for future value of annuity

3137.25 = 100x{(1.045)ⁿ-1}/.045

 (1.045)ⁿ = 2.4117625.

Now multiply 1.045 as many times till you get 2.4117625. No of times you multiply is your answer i.e. 20 years.

Its 20 years for caculation take calculater an and now do the same untill you type 100 for 20 times (do on caculater only)
 

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