Question 185481
Remember, if C is subset of D and D is a subset of C, then sets C and D are the same sets (draw a picture if you're unsure). In notation form, this looks like:


If *[Tex \LARGE C \subseteq D] and *[Tex \LARGE D \subseteq C], then *[Tex \LARGE C = D]


a) So n(C)=5 also tells us that n(D)=5 (ie the number of elements in sets C and D is 5) since C=D


b) The other relation ship is that C=D