Answer:
Years = natural log (total / principal) / rate
Years = natural log (50,000 / 20,000) / .17
Years = natural log (2.5) / .17
Years = (0.9162907319) / .17
Years = 5.3899454818 =
Years = 5.4 (rounded)
Source: https://www.1728.org/rate2.htm
Step-by-step explanation: