I start as a prime number. If you reverse my digits, I become a different prime number. The sum of my digits is 8. What number am I?
17 (or 71)
The two-digit numbers whose digits sum to 8 are 17, 26, 35, 44, 53, 62, 71, and 80. Of these, 17 and 71 are prime, and reversing 17 gives 71, which is also prime.
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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