Question

15/16 is 1 sixteenth groups of what size?

Answer 1

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.