Question

what is the HCF or GCF of 33, 55, 77
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Answer 1

The instructions to find the GCF of 33, 55 and 77 are the next:

1. Decompose all numbers into prime factors

33311111 55511111 77711111

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

Prime factors of 33=3 . 11Prime factors of 55=5 . 11Prime factors of 77=7 . 11

3. Choose the common prime factors with the lowest exponent

Common prime factors: 11

Common prime factors with the lowest exponent: 111

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 = 111 = 11

Answer 2

Step by Step Solution:
More Icon
Calculate Greatest Common Factor for :

33, 55 and 77


Factorize of the above numbers :

33 = 3 • 11
55 = 5 • 11
77 = 7 • 11
Build a prime factors table

Number of times each prime factor
appears in the factorization of :
Prime
Factor Number
33 Number
55 Number
77 G.C.F
(min)
3 1 0 0 0
5 0 1 0 0
7 0 0 1 0
11 1 1 1 1
GCF = 11
Greatest Common Factor is :
11