The population of a city is growing exponentially, increasing at the rate of 1.6% per year. A new bicycle route must be in place before the population doubles from its current value. How long (rounded up to the nearest year) does the city have before the new bicycle route must be completed?

Question

Quizplus · Accepted Answer

The doubling time for an exponentially growing quantity can be calculated using the rule of 70, which states that the doubling time (in years) is approximately 70 divided by the annual growth rate (in percent). For a growth rate of 1.6%, the doubling time is 70 / 1.6 = 43.75 years. Rounding up gives 44 years.

The Population of a City Is Growing Exponentially, Increasing at the Rate