What number does not belong out of these numbers decimal 15 the fraction 3 over 2 the fraction 3 over 2 and 150 percent?

Answer 1

The decimal 15

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Answer #2:

I agree 50/cos(60) percent with the first answer, but I see another possibility:

I'll say it's the number you intended to write instead of writing "the fraction 3 over 2" twice.

As it is, all the choices listed can be written with the digit-pair ' 15 ' in some form, so
it's not too much of a stretch to suggest that everything we see on the list does belong.