Leveraged Buyout · Private Equity Investing
Rule Of 72
How long does it take an investment to double when it compounds at a 9 percent annual return?
Interview question
- Difficulty
- Easy
- Topic
- Leveraged Buyout
- Subtopic
- Private Equity Investing
What this question trains
This problem practices a classic mental math shortcut used in finance interviews, the idea of estimating how long it takes money to grow at a given annual return. Candidates need to recognize when a quick approximation is appropriate, translate a percentage return into a time estimate, and think through the relationship between compounding and growth over time. Interviewers ask questions like this to test numeracy, comfort with basic investment concepts, and the ability to make fast back of the envelope estimates, all of which are useful in private equity and leveraged buyout discussions.