16 % of x = y% of 18

16x / 100 = 18y /100

Multiplying by 100 on both sides,

16x = 18y ==> 8x = 9y

So, y = 8x /9

Multiplying by 2 on both sides,

2y == 16x/9

Sqrt(x) and 2y ratio will be === sqrt(x) / 16x/ 9 ==== 9 *sqrt(x) / 16x

=== **9/16 *(sqrt(x))**

Thus value cant be determined without the value of x or y as above.