### Brain Teasers

# Bob and Rob

Bob is forty, Rob is thirteen. How many years ago was Bob 4 times older than Rob?

### Answer

4 years ago.Bob 36

Rob 9

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## Comments

hey Raynee, how can some one who has 101 rebus puzzles in their teaser list, accuse any one of favouring simple puzzles. Any one can stick two words together and call it a puzzle. The only tedious thing on this site is your proclivity to whine on regardless of the lack of subject matter.

uh oh... tension between the big shots....

Bob is forty, Rob is thirteen. How many years ago was Bob 4 times older than Rob?

40 - x = 4(13 - x)

40 - x = 52 - 4x

3x = 12

x = 4

Therefore, 4 years ago Rob was 4 times older than Rob.

40 - x = 4(13 - x)

40 - x = 52 - 4x

3x = 12

x = 4

Therefore, 4 years ago Rob was 4 times older than Rob.

This didn't even take simple algebra. Just figure the age difference between the two and realize that was equal to 3x the younger one's age at the time in question. I'm sure you can make them more challenging.

What's with this obsession to use algebra for simple arithmetical calculations?

Easy

Answer is 4

Answer is 4

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