Problem 44861. Ratio between sums of prime and non-prime numbers

Created by Jesús Zambrano

Solve Later

Write a function that calculates the ratio between the sum of the prime numbers less than or equal to x, and the sum of the non-prime numbers up to the greatest prime less than or equal to x.
For example, if x = 7, then:
sum_prime = sum([2 3 5 7]) = 17
sum_non_prime = sum([1 4 6]) = 11
Therefore, the desired ratio is:
prime_ratio = sum_prime / sum_non_prime = 17 / 11

Solve

Solution Stats

98 Solutions
39 Solvers

Last Solution submitted on Jun 12, 2025

Last 200 Solutions

Problem Comments

3 Comments

3 Comments

Gergely Patay on 28 Jun 2019

test case #2 is not correct.

Rafael S.T. Vieira on 27 Aug 2020

The problem description should be change to "and the sum of non-prime numbers up to the greatest prime lower than x".

goc3 on 29 Sep 2020

Thank you for that clarification, @Rafael S.T. Vieira. The problem title and description have been improved, along with added test cases.

Solution Comments

Show comments

Problem Recent Solvers39

Problem Tags

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Problem 44861. Ratio between sums of prime and non-prime numbers

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers39

Suggested Problems

More from this Author11

Problem Tags

Community Treasure Hunt

Problem 44861. Ratio between sums of prime and non-prime numbers

Solution Stats

Last 200 Solutions

Problem Comments

Solution Comments

Problem Recent Solvers39

Suggested Problems

More from this Author11

Problem Tags

Community Treasure Hunt

Players