find the gcf and lcm of 20 and 12
Mathematics · Middle School · Tue Nov 03 2020
Answered on
Answer: the LCM of 20 and 12 is 60. The GCF of 20 and 12 is 4.
First we need to define LCM and GCF. LCM is the least number the smallest number that is a multiple of both these values; it is the multiple common to the two values. While GCF is the common factor of the values.
How to solve:
For LCM: 20 and 12, list the prime factors of each number. Prime factors of 12 are 2, 3. Prime factors of 20 are 2, 5. Now multiplying the highest exponent prime factors to calculate the LCM of 12 and 20.
LCM(12,20) = 22 × 31 × 51
LCM(12,20) = 60
For GCF: 20 and 12, list the positive integer factors of 12 that divides 12 without a remainder; 1, 2, 3, 4, 6. Same with 20; 1, 2, 4, 5, 10.
Now that we listed the factors of 12 and 20, the biggest factor will be the GCF. Therefore 4 is the GCF of 12 and 20.