Maths Week Challenge 3 – The Spooky School


14 Oct 2015

It’s Maths Week! We’ve teamed up with University College Cork — currently celebrating the bicentenary of the birth of noted mathematician George Boole – to bring you maths challenges every day of the week. Today, as it’s hump day, we have one that’s a little bit more fun.

Wednesday’s Maths Week Challenge

During Halloween, four strange characters visit a school: a witch, a goblin, a ghost and a black cat.

Each of them goes into exactly one of these rooms, and only one of these rooms: Classroom 2, Classroom 3, Classroom 4 and the staff room.

The goblin stole a notebook. The cat painted its paws. The ghost hid in a desk. The witch left a present.

Clue 1: Nothing was stolen from Classroom 4
Clue 2: The ghost hid in either Classroom 2 or the staff room
Clue 3: Classroom 2 was not visited by the goblin
Clue 4: No notebooks or paints are ever kept in the staff room
Clue 5: The black cat prowled through one of the lower-numbered classrooms

Where did each of them go?

Today’s Maths Week Challenge comes courtesy of Dr Anca Mustata, UCC School of Mathematical Science and Maths Circles Ireland.

Make sure to check back in tomorrow for the solution to today’s Challenge.

Update: For the solution to Maths Week Challenge 3, click here.

Solution to Tuesday’s challenge

King Rumbo should call the people wearing 7, B and C.

If the person wearing 7 on one side is not wearing an A on the other side, then he or she is cheating.

If the person wearing B on one side happens to wear 7 on the other side, then he or she is also cheating for not wearing A. The same can be said for the person wearing C.

By contrast, the people wearing A on one side are allowed to wear anything on the other side – it could be 7, but it could just as well be anything else. The rule is only broken if someone wears 7 on one side but doesn’t wear A on the other.

Main image via Shutterstock