If you double me and subtract four, the answer is identical to what you get if you halve me and add eight. What number am I?
8
Translate to algebra: 2x - 4 = (x / 2) + 8. Subtracting x/2 from both sides gives 1.5x - 4 = 8, so 1.5x = 12, which simplifies to x = 8.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Easy. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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