I am a two-digit prime number. Reverse my digits, and I am still prime. My tens digit is greater than my units digit, and the sum of my digits is 10. What number am I?
73
Digit pairs adding to 10 with tens > units are 91 (composite), 82 (even), 73 (prime), 64 (even). 73 reversed is 37, 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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