Use some thinking to answer the following question. From the set of numbers x, y, t, z, p, q, r and w, how many different combinations can we have without the t,p,q and r in them? Ex:. (x,y), (x), (w,z,y,x), etc and (x,y)=(y,x)\nOptions:\n(A) 10\n(B) 12\n(C) 15\n(D) 16\n(E) 30
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Another way: Any letter (x, y, z, w) can be included or not. So, we have 2^4 combinations - 4 empty combination = 12 combinations So the final answer is (B).
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