You are earning 14% on your money. How long will it take to double your money?

Quick answer (approximate)

Use the rule of 72 to calculate the time=72/14=5.14 years

Accurate answer, assuming compounding period is annual

and using the compound interest formula

2000=1000 (1+0.14) ^n

Transpose

(1.14) ^n=2

n=log (2) / log (1.14) = 5.29 years