If 3/8 ARE wearing white schoes
Then 5/8 AREN'T wearing white shoes
because
8/8 - 3/8 = 5/8
8/8 is the same as 1
Therefore,
5/8 x 216/1 = y
If this is mental maths then,
You can cancel the 216 by 8 because the denominator of 5/8 is 8 to make 27
Therefore, the answer is 135