If angela has $500 to invest at 2.5% per annum compounded quarterly, how long will it be before she has $750?

N = number of compounding periods
Years = log (total / principal) / n * log (1 + rate / n)
Years = log (750 / 500) / 4 * log (1 + .025/n)
Years = log (1.5) / 4 * log (1.00625)
Years = 0.17609125906 / 4 * 0.0027058933759
Years = 0.17609125906 / 0.0108235735
Years = 16.2692348382

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