I've attached a question that I'm making some of my students try out, and I'm wondering if there is enough information given in the problem. The way we came up with requires the assumption of closure, which is not given.

Is closure required in order to do this problem? If not, can you show this without closure?

Question

I've attached a question that I'm making some of my students try out, and I'm wondering if there is enough information given in the problem. The way we came up with requires the assumption of closure, which is not given. 

Is closure required in order to do this problem? If not, can you show this without closure?

anonymous · Answer

attachment

anonymous · Answer

it already tells you that it is closed.

xy is among the colors of a,b,c

anonymous · Answer

Ah, we all missed that!
Thanks!

anonymous · Answer

youre welcome