I am a two-digit number. Reversing my digits produces a number that is 36 greater than my original value. The sum of my digits is 10. What original number am I?
37
Let the original number be 10x + y. We are given x + y = 10 and (10y + x) - (10x + y) = 36, which simplifies to 9(y - x) = 36 or y - x = 4. Solving x + y = 10 and y - x = 4 gives x = 3 and y = 7, making the original number 37.
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: Medium. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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