Copyright © University of Cambridge. All rights reserved.

'Birthday Party' printed from https://nrich.maths.org/

Show menu

Answer: 6

There must be 25 pupils who all have different birthdays. If the remaining 5 pupils all have the same birthday as one of these pupils, then 6 pupils will share the same birthday.
This problem is taken from the UKMT Mathematical Challenges.
You can find more short problems, arranged by curriculum topic, in our short problems collection.