The GCF is found between 2 or more numbers, not just one. If we are looking for the GCF of 64 and 152, for example, we will list all the factors of each number and then pick the greatest (largest) one that is repeated in each number. The factors of 64 are:
1,64 2,43 4,16 8,8
The factors of 152 are:
1,152 2,76 4,38 8,19
The GCF of both those numbers is 8. 2 is in both, and so is 4, but 8 is the largest, so that's the GCF. GCF is found by finding the factors of the numbers and picking the biggest one that is repeated in both.
We have a total of 72+81+5=158 males and 103+68+7=178 females surveyed. That's a total n = 158 + 178 = 336.
Assuming this is a representative population, we have 72 males in favor which we combine with the 178 females for a total 72+178=250 people that are female or in favor. So our probability is