Question

A bank account is growing by 4.3 % per year. Find the doubling time.


Round your answer to the nearest integer.

Can someone explain how to solve this step by step. I have been stuck on this for quite a while

Answer 1

1.043^n = 2
n log 1.043 = log 2

n = log 2/log 1.043 = 16.5 years

Answer 2

you want 1.043^t = 2.0
t log 1.043 = log 2
t = log2/log1.043 = 16.5 years

This is roughly in accordance with the rule of 72: 72/4.3 = 16.7