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Reversible Primes

Age 11 to 14 Short
Challenge Level

The integer 113 is prime, and its reverse, 311, is also prime.

How many two-digit primes are there between 10 and 99 which have the same property?





This problem is taken from the UKMT Mathematical Challenges.
You can find more short problems, arranged by curriculum topic, in our short problems collection.
The NRICH Project aims to enrich the mathematical experiences of all learners. To support this aim, members of the NRICH team work in a wide range of capacities, including providing professional development for teachers wishing to embed rich mathematical tasks into everyday classroom practice.
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