Thinking between the Lines

16.07.2018 |

Episode #5 of the course The world’s most compelling logic puzzles by John Robin


Welcome back!

I hope you enjoyed yesterday’s extra in-depth exploration of Einstein’s Riddle. Today, we’re going to explore one that’s slightly similar, except instead of pure logic, this one combines logic and mathematics.

Here it is: Two old friends, Jack and Bill, meet after a long time.

“Hey, how are you?” Jack says.

“Not bad,” Bill replies. “I got married and I have three kids now.”

“That’s great!” Jack says. “How old are they?”

Bill pauses before replying: “The product of their ages is 72, and the sum of their ages is the same as your birth date.”

Jack laughs. “You expect me to figure that out?”

Bill gives Jack a peculiar look. Then he laughs too. “You’re right. Sorry about that. My eldest kid just started taking piano lessons.”

“Ah,” Jack says. “Now, that’s easy …”

Then he tells Bill how old his children are.

What is Jack’s reply? Work it out on your own first, then click the button below to find out if you’re right.

See the Answer

Tomorrow, we’ll try another famous problem based in math and careful word choice.


Recommended resource

Six Ingenious Logic Puzzles (you’ll recognize one of them!)


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