If you multiply my age by 3, then subtract 10, then divide by 2, you get my exact age plus 5. How old am I?
20
Let age be x. (3x - 10) / 2 = x + 5. Multiply by 2: 3x - 10 = 2x + 10. Subtract 2x and add 10: x = 20.
About this riddle
Logic riddles give you a few facts and ask what must be true. List what you know, cross out what cannot be, and see what is left.
Difficulty: Medium. More like this: Logic riddles with answers or try Einstein's Logic Grid for a different kind of puzzle.
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