This is 5th grade math. I worked on this for over an hour. The answer is supposed to be 30 but I don't get it. Paul, you are the doctor. Think you can solve it?
If I were to guess: The problem doesn't tell you which portions of the class like more than one choice, so I'd assume that they are asking for the best possible scenario of cheese lovers. So best case scenario is, if 60/90 love topping A, then the remaining 30/90 are left to love only cheese. And since we know that 70/90 do love cheese, it's not impossible for the 30 who don't like Topping A to be members of the group that like cheese. If we thought the answer was 40, for example, that would be incompatible with the 60/90 who like topping A, since 40/90 + 60/90 = 100/90 which is too many students. The cheese only members HAVE to be non-topping A lovers, so they have to represent the 30/90 who don't like topping A.
If I were to guess:
ReplyDeleteThe problem doesn't tell you which portions of the class like more than one choice, so I'd assume that they are asking for the best possible scenario of cheese lovers.
So best case scenario is, if 60/90 love topping A, then the remaining 30/90 are left to love only cheese.
And since we know that 70/90 do love cheese, it's not impossible for the 30 who don't like Topping A to be members of the group that like cheese.
If we thought the answer was 40, for example, that would be incompatible with the 60/90 who like topping A, since 40/90 + 60/90 = 100/90 which is too many students.
The cheese only members HAVE to be non-topping A lovers, so they have to represent the 30/90 who don't like topping A.