this one is kind of tricky!
So we can select anything that fits within the confines of the requirements of the comedian. He wants at least 4 females and could use anywhere up to 10 if there are no males. Using the bare minimum of 4 females, he could use anywhere up to 6 boys. If there are 3 or less females, we assume there is no show. But there doesn't have to be any boys for the show as long as he has at least 4 females.
Okay. I think I've got it. Now let's look at each example and see if it fits the parameters above using x for females and y for males.
1. x (girls) is greater or less than 4. YES this fits.
2. y (boys) are greater than 0. Well, they could be, but remember we can do the show with NO boys so this doesn't work. NO.
3. x plus y is less than or equal to 10. That is true so YES.
4. y is greater or equal to 0. YES. (this is how #2 should have looked)
5. x is greater than 4. Well, it could be. But x can also be equal to 4 so this doesn't work. NO
6. x plus y is less than 10. It could be, but this doesn't allow for the possiblity that they could be equal to 10. So NO this does not work.
We have: 1, 3, 4 as correct models of the situation.