Saved 5: Introduction to Valuation: The Time Va... 3 At 6.7 percent interest, how long does it take to double your money? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) Length of time years eBook Print At 6.7 percent interest, how long does it take to quadruple it? (Do not round intermediate calculations and round your answer to 2 decimal places, e.g., 32.16.) References Length of time years