I am a two-digit number. If you reverse my digits, the new number is 18 greater than me. The sum of my original digits is 8. What number am I?
35
Let the number be 10t + u. Reversed is 10u + t. (10u + t) - (10t + u) = 18 => 9u - 9t = 18 => u - t = 2. We also know t + u = 8. Adding them gives 2u = 10 => u = 5, and t = 3. The number is 35.
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: Hard. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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