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jmc

number theory intermediate

Problem

To test whether an integer, , is prime, it is enough to be sure that none of the primes less than or equal to the square root of divide . If you want to check that a number between 900 and 950 is prime with this rule, what is the largest prime divisor you need to test?
Solution
You need to test the primes less than a number between and , so the largest prime divisor you need to test is .
Final answer
29