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Market Growth Rate CAGR questions but can't apply rule of 72

Compounded Annual Growth Rate
New answer on May 20, 2022
2 Answers
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Anonymous A asked on May 17, 2022

Hello all,

How would you solve the following in 1 min:

The market size is $50B and is expected to grow by 30% per year for the next 5 years? 

I got this question in a case interview and ended up doing the real math rather than using Rule of 72, which I thought wasn't applicable here, but I maybe wrong. My calculation took almost 2-3 mins.

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Ian
Expert
Content Creator
replied on May 18, 2022
#1 BCG coach | MBB | Tier 2 | Digital, Tech, Platinion | 100% personal success rate (8/8) | 95% candidate success rate

Hi there,

72 / 30 = 2.5

That means it doubles every 2.5 years.

As it turns out, the case question really conveniently asks you for the 5 year period…how convenient! (Sarcasm…it's planned!)

So, your investment will double twice.

The answer is $200B

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Clara
Expert
Content Creator
replied on May 20, 2022
McKinsey | Awarded professor at Master in Management @ IE | MBA at MIT |+180 students coached | Integrated FIT Guide aut

Hello!

The rule still applies! You need to see that 2.5 times 30 is approx. 72 (75, but we need to train the eye to see this kind of “almost” in the math, since they are the trick)

 

Cheers, 

Clara

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Ian gave the best answer

Ian

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