What's new

A crowded bus brainteaser

By , 24 November 2021

Difficulty: Fun

The number 39 bus was packed as it pulled into the interchange. Then 37 people got off, and another 14 got on. As the bus left the interchange, there were 37 people on board.

How many people were on the bus as it pulled into the interchange?

Scroll down or click for a hint, or the answer!


brain icon

Brainteaser hint

Start with 37 people on the bus and work backwards in time! Remember to add the people getting off, and subtract the people getting on – everything is backwards.

brain icon


Brainteaser answer

To solve this brainteaser, we’re going to work backwards in time.

When the bus left there were 37 people on board. Just before the bus left, 14 people got on. Before they did, there must have been 37 – 14 = 23 people on the bus.

Before those people got on the bus, 37 people got off. So initially there must have been 23 + 37 = 60 people on the bus.

60 people is the answer! To check, we can run the story forwards.

60 – 37 + 14 = 37

For more brainteasers and puzzles for kids, subscribe to Double Helix magazine!

Subscribe now! button


Leave a Reply

By posting a comment you are agreeing to the Double Helix commenting guidelines.

This site uses Akismet to reduce spam. Learn how your comment data is processed.