The diagram shows a large rectangle composed of nine identical smaller rectangles.

Both the length and breadth of each of these smaller rectangles are whole numbers of centimetres. Which of the following could be the area of the large rectangle?

a. 450 square centimetres

b. 1260 square centimetres

c. 1620 square centimetres

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.

You can find more short problems, arranged by curriculum topic, in our short problems collection.