The formula below tells us how to obtain the maturity value on a simple discount loan if we are given the proceeds, the discount rate, and the term.

M = P 1 d R T

If a loan's annual simple discount rate is 1.75%, how many years would it take for the debt to double? (This is called the doubling time of a loan).

Round your answer to the nearest tenth of a year.

Hint: divide both sides of the equation by P. If M is twice as much as P, what should the fraction on the left-hand side equal?