Formula, method and derivation to find the number of ways in which a positive integer can be expressed as a product of two co prime factors. Factors that are relatively prime to each – i.e., two factors whose HCF is 1.

The Method
Step 1: Prime factorize the given number.
Step 2: Count the number of prime factors. Let us say the number has ‘x’ prime factors. Note, count only the prime factors.
For example, if the number is 28, it can be prime factorized as 2^2 * 7. 28 has 2 prime factors viz., 2 and 7.
Step 3: Number of ways of expressing the number as product of 2 co prime factors = 2^(x – 1), where x is the number of prime factors of the number.

The video not just gives you this formula but also derives the formula provides the logic behind why the method works.

Looking for more sample GMAT Number Properties practice questions? Visit

Sign up for the most comprehensive and affordable online GMAT quant course @ and ace GMAT maths section.

Free GMAT verbal and GMAT quant practice questions @

Join Wizako’s Intensive Weekend and Weekday GMAT coaching classes for GMAT quant and GMAT verbal at Chennai. Details of next batch @

#GMATQuantTutorials #GMATMathLessons #GMATNumberProperties #GMATNumberTheory


Fill this form and get best deals on " Coaching classes"

  • 100% genuine institutes aiming to help you ace studies
  • Get immediate response from the institutes
  • Compare institutes and pick only the best!
  • Feel free to choose the institute you like, and rest will be taken care of
Verify Yourself

Log in with your credentials


Forgot your details?

Create Account