Prime numbers 2 is the smallest prime number 2 is the only prime even number 1 is not a prime 3, 5, 7 are the only three consecutive odd integers that are each a prime. Digits In the integer 5,432, 5 is the thousands digit, 4 is the hundreds digit, 3 is the tens […]

# Archive | Prime Numbers

## Prime Numbers and Probability – GRE Math Problem

By Chris Lele on May 18, 2011 , UPDATED ON April 3, 2012, in Combinations and Permutations, Integer Properties, Math Concepts, Prime Numbers, Probability

Oftentimes, math problems will require that you know more than one concept. Sometimes, you’ll have to know the difference between an integer and a number in order to get the question right. Below, I’ve combined prime numbers with probability, two subjects already covered in this blog. The question below isn’t easy and actually takes a […]

## Think You Know Your Prime Factors?

By Chris Lele on February 9, 2011 , UPDATED ON October 11, 2018, in Integer Properties, Math Concepts, Prime Numbers

Here is a good problem to test your understanding of prime factors, not to add multiples. See if you can finish the problem in less than 2 minutes. If P is the product of all of the positive multiples of 11 less than 100, then what is the sum of the distinct prime factors of […]