Difficulty: Fun
Tommy’s part of a group that’s out breaking the rules. They’re going for a ride together instead of social distancing.
Each member is on their own vehicle. Some of them are riding bikes and some are riding trikes, with three wheels instead of two.
If there are 22 riders and 47 wheels, how many people are riding trikes?
Scroll down or click for a hint, or the answer!
Brainteaser hint
How many wheels would there be if everyone was riding a bike?
Brainteaser answer
Every rider has at least two wheels on their vehicle. With 22 riders each riding a bike, there would be 44 wheels all together.
But there are actually 47 wheels. 47 – 44 = 3 so there are three more wheels than if everyone was riding a bike. We can use those three extra wheels to make three bikes into trikes.
We can check this makes sense:
3 trikes + 19 bikes = 22 riders
(3 x 3) + (19 x 2) = 47 wheels
So, the answer is: there are 3 people riding trikes.
For more brainteasers and puzzles for kids, subscribe to Double Helix magazine!
Leave a Reply