Which of the following pairs of numbers has a greatest common divisor (GCD) of 1
Practice Questions
Q1
Which of the following pairs of numbers has a greatest common divisor (GCD) of 1?
8 and 12
15 and 28
9 and 27
10 and 20
Questions & Step-by-Step Solutions
Which of the following pairs of numbers has a greatest common divisor (GCD) of 1?
Step 1: Understand what GCD means. GCD stands for Greatest Common Divisor, which is the largest number that can divide two numbers without leaving a remainder.
Step 2: Identify the two numbers you are checking. In this case, the numbers are 15 and 28.
Step 3: List the divisors of each number. The divisors of 15 are 1, 3, 5, and 15. The divisors of 28 are 1, 2, 4, 7, 14, and 28.
Step 4: Find the common divisors between the two lists. The only common divisor of 15 and 28 is 1.
Step 5: Determine the greatest common divisor. Since the only common divisor is 1, the GCD of 15 and 28 is 1.
Step 6: Conclude that since the GCD is 1, the numbers 15 and 28 are coprime.
