15/16 is 1 sixteenth groups of what size?

Let X be the size we want to find so,

15 / 16 = 1/16 x (X)

multiplying both sides with 16 we get, 15 = X

so 15 is the answer.

there is another way to find the answer if we divide 15 / 16 with 1 / 16, we get the answer which is 15 from this method also.