Question

Exercise 2
Find the H.C.F. of the following numbers.
1. 480.540 and 600.
2. 28. 84 and 98.
3. 180 and 288.
4. 54, 126 and 162.
5. 84, 156 and 204.
6. 4017.2163 and 3399.
7. 66.99 and 114.
8. 99, 108, 405 and 315.​

Answer 1

Answer:

. Decompose all numbers into prime factors

126 2 63 3 21 3 7 7 1 162 2 81 3 27 3 9 3 3 3 1 180 2 90 2 45 3 15 3 5 5 1

2. Write all numbers as the product of its prime factors

Prime factors of 126 = 2 . 32 . 7

Prime factors of 162 = 2 . 34

Prime factors of 180 = 22 . 32 . 5

3. Choose the common prime factors with the lowest exponent

Common prime factors: 2 , 3

Common prime factors with the lowest exponent: 21, 32

4. Calculate the Greatest Common Factor or GCF

Remember, to find the GCF of several numbers you must multiply the common prime factors with the lowest exponent.

GCF = 21. 32 = 18