Final answer:
The duration of the loan was 0.5 years, or 6 months, calculated using the simple interest formula with the given values of $6,000 principal, 14% interest rate, and $420 interest paid.
Step-by-step explanation:
To calculate the duration of the loan, we need to use the formula for simple interest which is I = PRT, where I is the interest, P is the principal amount, R is the rate of interest per year, and T is the time period in years.
The man borrowed $6,000 at 14% simple interest per year and paid $420 in interest. Using the formula, we get: $420 = $6,000 * 14% * T. To find T, we rearrange the formula to T = I / (P * R), which gives us T = $420 / ($6,000 * 0.14) T = $420 / $840 T = 0.5 years.
Therefore, the duration of the loan was 0.5 years, which is equivalent to 6 months.