Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3
grid so that all the rows and columns add up to a prime number. How
many different solutions can you find?
An ordinary set of dominoes can be laid out as a 7 by 4 magic
rectangle in which all the spots in all the columns add to 24,
while those in the rows add to 42. Try it! Now try the magic
Can you spot the similarities between this game and other games you
know? The aim is to choose 3 numbers that total 15.
Walking up a steep hill, I pass 10 equally spaced street lamps. I take 5 seconds to walk from the first lamp to the second lamp, 6 seconds from the second lamp to the third, and so on, with each time increasing by 1 second as I slow down. How long do I take to walk from the first lamp to the last?
If you liked this problem, here is an NRICH task which challenges you to use similar mathematical ideas.
This problem is taken from the UKMT Mathematical Challenges.