Final answer:
To reduce the fraction 21/24, divide both the numerator and denominator by their greatest common divisor (GCD), which is 3. The simplified form of the fraction is 7/8.
Step-by-step explanation:
To reduce the fraction 21/24, we need to find the greatest common divisor (GCD) of 21 and 24, which is 3. We can divide both the numerator and the denominator by 3 to simplify the fraction. Dividing 21 by 3 gives us 7, and dividing 24 by 3 gives us 8. Therefore, the simplified form of 21/24 is 7/8.