Quiz on Gcf

What is the purpose of understanding GCF and LCM in mathematics?

• To discuss number relationships in multiplication and division

• To solve algebraic equations

• To calculate area and perimeter

• To measure angles

What is the main focus of the lesson on Tuesday?

• Finding common factors and multiples

• Solving equations

• Learning about geometry

• Studying fractions

What does GCF stand for?

• Greatest Common Factor

• Greatest Common Fraction

• Greatest Common Formula

• Greatest Common Function

What is the greatest common factor (GCF) of 24 and 36?

• 2

• 6

• 12

• 18

Answer explanation

To find the GCF of 24 and 36, list the factors: 24 (1, 2, 3, 4, 6, 8, 12, 24) and 36 (1, 2, 3, 4, 6, 9, 12, 18, 36). The greatest common factor is 12, as it is the largest number in both lists.

If you have two numbers, 15 and 25, what is their GCF?

• 1

• 5

• 10

• 15

Answer explanation

The GCF (Greatest Common Factor) of 15 and 25 is 5, as it is the largest number that divides both without leaving a remainder. The factors of 15 are 1, 3, 5, 15 and for 25 are 1, 5, 25. The common factor is 5.

John has 18 apples and 24 oranges. He wants to make fruit baskets with the same number of each fruit in every basket. What is the greatest number of baskets John can make?

• 2

• 3

• 6

• 9

Answer explanation

To find the greatest number of baskets, we need the greatest common divisor (GCD) of 18 and 24. The GCD is 6. Thus, John can make 6 baskets with 3 apples and 4 oranges in each. However, he can also make 9 baskets with 2 apples and 2 oranges each.

Sarah has two ribbons, one 12 feet and another 15 feet long. She wants to cut both ribbons into pieces of the same length without any leftover ribbon. What is the greatest length each piece can be?

• foot

• 3 feet

• 6 feet

• 9 feet

Answer explanation

To find the greatest length for each piece, we need the greatest common divisor (GCD) of 12 and 15. The GCD is 3. However, the largest piece length that divides both ribbons without leftovers is 6 feet, as it fits into both lengths evenly.

What is the GCF of 42 and 56?

• 7

• 14

• 21

• 28

Answer explanation

To find the GCF of 42 and 56, we list their factors. The factors of 42 are 1, 2, 3, 6, 7, 14, 21, 42, and for 56 they are 1, 2, 4, 7, 8, 14, 28, 56. The greatest common factor is 14.

Find the greatest common factor of 30 and 36.

• 2

• 3

• 6

• 18

Answer explanation

To find the greatest common factor (GCF) of 30 and 36, we list their factors: 30 (1, 2, 3, 5, 6, 10, 15, 30) and 36 (1, 2, 3, 4, 6, 9, 12, 18, 36). The largest common factor is 6.

greatest common factor of 20 and 30.

• 2

• 5

• 10

• 15

Answer explanation

To find the greatest common factor (GCF) of 20 and 30, we list their factors: 20 (1, 2, 4, 5, 10, 20) and 30 (1, 2, 3, 5, 6, 10, 15, 30). The largest common factor is 10.