Identifying and Applying Coprime Numbers

  • 8th Grade
Reviewed by Editorial Team
The ProProfs editorial team is comprised of experienced subject matter experts. They've collectively created over 10,000 quizzes and lessons, serving over 100 million users. Our team includes in-house content moderators and subject matter experts, as well as a global network of rigorously trained contributors. All adhere to our comprehensive editorial guidelines, ensuring the delivery of high-quality content.
Learn about Our Editorial Process
| By Thames
T
Thames
Community Contributor
Quizzes Created: 7387 | Total Attempts: 9,527,791
| Attempts: 11 | Questions: 20 | Updated: Nov 7, 2025
Please wait...
Question 1 / 20
0 %
0/100
Score 0/100
1) Which of the following pairs is coprime?

Explanation

14 = 2 × 7 and 25 = 5 × 5. They share no common factors, so they’re coprime.

Submit
Please wait...
About This Quiz
Identifying And Applying Coprime Numbers - Quiz

Did you know two numbers don’t have to be prime to be coprime? In this quiz, you’ll explore pairs of numbers that share no factors except 1, test real examples, and connect the idea of coprimes to GCD. Take this quiz to sharpen your number sense and see how coprime... see morerelationships appear in surprising ways.
see less

2)
You may optionally provide this to label your report, leaderboard, or certificate.
2) Which pair is not coprime?

Explanation

16 = 2⁴, 24 = 2³ × 3. They share 2’s, so they’re not coprime.

Submit
3) Which of these sets are all coprime pairs?

Explanation

Each pair has no shared factor — they’re all coprime.

Submit
4) Which pair is coprime even though one number is composite?

Explanation

9 = 3² and 16 = 2⁴. Different prime factors but both composite → coprime.

Submit
5) Which number is coprime to 35?

Explanation

35 = 5 × 7; 22 = 2 × 11. No shared factors → coprime.

Submit
6) If GCD(21, x) = 1, which x value makes them coprime?

Explanation

21 = 3 × 7, and 10 = 2 × 5. No shared factors, so they’re coprime.

Submit
7) If two numbers are coprime, their GCD is always:

Explanation

That’s the definition — their only common factor is 1.

Submit
8) Which is a coprime pair?

Explanation

8 = 2³; 15 = 3 × 5 → no shared factors → coprime.

Submit
9) Which of these pairs are coprime?

Explanation

Both pairs share no common primes → both are coprime.

Submit
10) Which statement about coprime numbers is true?

Explanation

True statement about coprime numbers → “They share no common factors except 1.”

Submit
11) If numbers a and b are coprime, which is always true?

Explanation

They have no overlap in factors, so multiply directly for the LCM.

Submit
12) Which of the following pairs is coprime?

Explanation

11 = prime; 18 = 2 × 3². No common factors → coprime.

Submit
13) Which pair is coprime?

Explanation

19 = prime; 42 = 2 × 3 × 7 → no shared factors → coprime.

Submit
14) If GCD(14, n) = 1, then n could be:

Explanation

14 = 2 × 7; 9 = 3² → no shared primes → coprime.

Submit
15) Which consecutive numbers are coprime?

Explanation

Consecutive numbers always differ by 1 → no shared factors.

Submit
16) Which pair is not coprime?

Explanation

15 = 3 × 5; 45 = 3² × 5 → many common factors.

Submit
17) If GCD(a, b) = 1, what can you say about a and b?

Explanation

If GCD(a, b) = 1 → They are coprime.

Submit
18) Which pair is coprime?

Explanation

9 = 3²; 28 = 2² × 7 → no shared factors.

Submit
19) Which is not a coprime pair?

Explanation

Both have 2’s as factors → not coprime.

Submit
20) Which of these pairs is coprime?

Explanation

(5,12), (6,13), (8,15) each have no shared factors.

Submit
×
Saved
Thank you for your feedback!
View My Results
Cancel
  • All
    All (20)
  • Unanswered
    Unanswered ()
  • Answered
    Answered ()
Which of the following pairs is coprime?
Which pair is not coprime?
Which of these sets are all coprime pairs?
Which pair is coprime even though one number is composite?
Which number is coprime to 35?
If GCD(21, x) = 1, which x value makes them coprime?
If two numbers are coprime, their GCD is always:
Which is a coprime pair?
Which of these pairs are coprime?
Which statement about coprime numbers is true?
If numbers a and b are coprime, which is always true?
Which of the following pairs is coprime?
Which pair is coprime?
If GCD(14, n) = 1, then n could be:
Which consecutive numbers are coprime?
Which pair is not coprime?
If GCD(a, b) = 1, what can you say about a and b?
Which pair is coprime?
Which is not a coprime pair?
Which of these pairs is coprime?
Alert!

Advertisement