Explanation

We use the word "is" in both statements to denote an equal sign. "x is 2k percent of y" becomes



We can confirm considering, "x is 80 percent of y." If we plug in the 80, it's correct. The statement we are looking for starts with "k is," or k=, so let's isolate k.







In order to be able to pluck a percent out of the portion in parentheses, the denominator must be 100. But it's 2y, so we will multiply by a form of 1 that will make the denominator 100:





It looks odd, but now the numerator of is the answer. The variable k is of x.

The correct answer is (E).