Skip over navigation
Every second meal I will have soup for my starter.
Every $5$th meal I will have pasta for my main course.
Every $3$rd meal I will have crumble for my dessert.
$2, 5$, and $3$ have no common factors, so I will have eaten $2\times5\times3=30$ school dinners (the Lowest Common Multiple) before I sit down to the same combination again.
School Dinners
Age 11 to 14
ShortChallenge Level 
Every second meal I will have soup for my starter.
Every $5$th meal I will have pasta for my main course.
Every $3$rd meal I will have crumble for my dessert.
$2, 5$, and $3$ have no common factors, so I will have eaten $2\times5\times3=30$ school dinners (the Lowest Common Multiple) before I sit down to the same combination again.
This problem is taken from the UKMT Mathematical Challenges.
You can find more short problems, arranged by curriculum topic, in our short problems collection.
You may also like
Consecutive Numbers
An investigation involving adding and subtracting sets of consecutive numbers. Lots to find out, lots to explore.
Days and Dates
Investigate how you can work out what day of the week your birthday will be on next year, and the year after...