## Office Hours: Rule of 70

One of the of the practice questions from our "Growth Rates Are Crucial" video asks you to compare real GDP per capita for two countries that start at the same

One of the of the practice questions from our "Growth Rates Are Crucial" video asks you to compare real GDP per capita for two countries that start at the same place, but grow at different rates. It’s a little tricky:

Suppose two countries start with the same real GDP per capita, but country A is growing at 2% per year and country B is growing at 3% per year. After 140 years, country B will have a real GDP per capita that is roughly ________ times higher than country A. (Hint- you may want to review the “Rule of 70” to answer this question.)

We asked our Instructional Designer, Mary Clare Peate, to hold virtual “office hours” to guide you through how to solve this problem. Join her as she discusses your questions!

Is there a different practice problem that has you stuck? Suggest a topic for our next office hours in the comments below.