Answer: 6 should be your answer
Explanation: Depending on how many and how large the numbers are, there are a variety of approaches to compute the GCF of a collection of integers.
Simply look at each number's components or multiples to get its largest common multiple for lesser numbers.
These factors look like this for 6 and 42:
1, 2, 3, and 6 are the six factors.
1, 2, 3, 6, 7, 14, 21, and 42 are the 42 factors.