You are tearing down a building and find $1 in change that someone lost when working on the building 140 years ago. If, instead of being careless with the $1 in change, this person had deposited it into a bank and earned 2 percent interest every year for 140 years, how much would be in the account today according to the rule of 70?
A)$4
B)$8
C)$16
D)$32

Question

Quizplus · Accepted Answer

The rule of 70 estimates the doubling time of an investment by dividing 70 by the interest rate. At 2% interest, the money doubles approximately every 35 years (70/2). In 140 years, the money would double 4 times (140/35), resulting in $16.

You Are Tearing Down a Building and Find $1 in Change