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Adding and Multiplying

Age 11 to 14 Short
Challenge Level

Amy was asked to multiply a number by 8 and then add 5.
Instead, she added 8 to the number, then multiplied the result by 5.
This gave her 2015.

What would the answer have been if Amy had followed the instructions correctly?

This problem is adapted from the World Mathematics Championships
You can find more short problems, arranged by curriculum topic, in our short problems collection.