MEDIUM
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IMPORTANT
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What is the smallest positive integer x for which x2-x+5 is not a prime?

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Important Questions on Number System

HARD
IOQM - PRMO and RMO
IMPORTANT
What is the smallest composite number generated by p2-p-1, where p is a prime?
HARD
IOQM - PRMO and RMO
IMPORTANT
Some prime numbers are 1 more than a square, as in 42+1=17. How many primes p100 are of the form p=n2+1?
EASY
IOQM - PRMO and RMO
IMPORTANT
How many prime numbers x satisfy 300<x<700?
HARD
IOQM - PRMO and RMO
IMPORTANT
The number of pairs of prime numbers (p, q) satisfying the condition 51100<1p+1q<56 will be
MEDIUM
IOQM - PRMO and RMO
IMPORTANT
The number of positive integers n'' for which 3n-4, 4n-5 and 5n-3 are all primes is
HARD
IOQM - PRMO and RMO
IMPORTANT
m, n are natural numbers. The number of pairs m,n for which m2+n2+2mn-2013m-2013n-2014=0 is
EASY
IOQM - PRMO and RMO
IMPORTANT
Suppose that a, b, c are distinct numbers such that b-a2-4b-cc-a=0, find the value of b-cc-a.
EASY
IOQM - PRMO and RMO
IMPORTANT
Suppose that p and q are prime numbers (p>q) and they are roots of the equation x2-99x+m=0 for some m. What is the value of p-q?