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Jewellery Boxes

Age 14 to 16 Short Challenge Level:

Two boxes, P and Q, each contain 3 jewels.
When a jewel worth £5000 is transferred from P to Q, the average value of the jewels in each box increases by £1000.

What is the total value of all six jewels?

This problem is taken from the UKMT Mathematical Challenges.
You can find more short problems, arranged by curriculum topic, in our short problems collection.