# This Simple Riddle Nearly Fooled Einstein So Here’s How To Solve It In Case You Want To Look Smart Some Day

iStockphoto / francescoch

In 1934, Austro-Hungarian psychologist Max Wertheimer wrote his dear friend Albert Einstein a letter and in that correspondence, he included a relatively simple and straight-forward riddle that somehow confounded one of the greatest thinkers in human history.

This clip comes from the MindYourDecisions YouTube channel and it starts out with him explaining the riddle. Later on, he explains how to solve the riddle. For now, I’ll break it down for you to see if you can solve it before you check out this clip.

There’s an old car that has to go up and down a hill. The hill is 1-mile going up and because the car’s old it can only average 15mph going up the hill. Presumably, the old car can go faster down the hill. The hill is 1-mile going down as well. His question is how fast must the car go down the hill in order to average 30mph for the entire 2-mile trip.

Perhaps, some of you are here to just learn the answer to this riddle. That’s fine. I’ll put it down below but I wanted to stretch this out a little bit for anyone that is looking to solve this and avoid any spoilers…

Keep scrolling

Keep Scrolling

Okay, that’s far enough. Well, Einstein wrote back that he didn’t see the ‘trick’ to this riddle until he calculated the answer which means that 1) Einstein had to undergo careful steps in order to solve and 2) Albert Einstein enjoyed this every step of the way.

To solve, he works backwards by determining the time necessary to average 30mph for a 2 mile trip. He does this by 30mph = 2 miles/t trip. That answer is 1/15th of an hour, or 4 minutes.

Then he solves for the time it takes the car to travel up the hill. For this, t ascent = 1 mile/15mph which simplifies to 1/15th of an hour which again is 4 minutes.

This means that the car has ZERO minutes to travel down the hill in order to average 30mph for the entire trip and thus it’s a trick question that Einstein couldn’t figure out until he ran the math.

Boom. Feel smarter? Sure, you do.

Cass Anderson is the Editor-in-Chief of BroBible. He covers an array of topics including NFL, Pop Culture, Fishing News, and the Outdoors.