16/c =8
That means 16 divided by same random number "c" makes the number 8. This also means that 8 times that random number you divided by makes 16.
Using this, you can rearrange the equation in various ways.
16/c =8
16 = c*8
c = 16/8
We only really need that last one, c = 16/8,
16/8 = 2
c = 2