What is the GCF of 75 and 20?
The greatest common factor of two or more non-zero integers, x & y, is the greatest positive integer m, which divides both, x & y
Answer: GCF(75 and 20) is 5
THere are many ways to find the GCF.LEt us see 2 methods to find the GCF of 75 and 20.
Prime factorization and long division are the commonly used methods to find GCF.
Method 1: Prime Factorisation:
- Write each number in the prime factorised form.
- Product of common factors taken once is the GCF
Prime Factorisation of 75: 3×5×5
Prime Factorisation of 20: 2×2×5
Product of Common Factors taken once: 5
GCF of 75 and 20 is 5
Method 2: Long Division Method:
- Divide 75 by 20 and check the remainder.
- In the next step of division, the remainder of the step 1 will act as the divisor and the divisor of the step 1 as the dividend and perform the long division again.
- Continue untill you get remainder as 0
- The last divisor will be the GCF.