Identifying and Applying Coprime Numbers

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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.

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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

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2) Which pair is not coprime?

Explanation

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

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3) 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.

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4) Which of these sets are all coprime pairs?

Explanation

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

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5) Which pair is coprime even though one number is composite?

Explanation

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

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6) Which number is coprime to 35?

Explanation

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

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

Explanation

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

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8) Which is a coprime pair?

Explanation

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

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9) Which of these pairs are coprime?

Explanation

Both pairs share no common primes → both are coprime.

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10) Which statement about coprime numbers is true?

Explanation

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

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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.

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12) Which of the following pairs is coprime?

Explanation

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

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13) Which pair is coprime?

Explanation

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

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

Explanation

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

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15) Which consecutive numbers are coprime?

Explanation

Consecutive numbers always differ by 1 → no shared factors.

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16) Which pair is not coprime?

Explanation

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

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

Explanation

If GCD(a, b) = 1 → They are coprime.

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18) Which pair is coprime?

Explanation

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

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19) Which is not a coprime pair?

Explanation

Both have 2’s as factors → not coprime.

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20) Which of these pairs is coprime?

Explanation

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

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Which of the following pairs is coprime?
Which pair is not coprime?
If GCD(21, x) = 1, which x value makes them 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 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?
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