3/8 as a percentage is 37.5%
Comparision of volume of sphere and cube=0.98820059
coparision of surface area of sphere and cone=0.807582012
Assume that the radius of the circle is 1.
The diagonal of the square is 2. By the Pythagorean Theorem, the side of the square of a right triangle will be 2/sqrt(2).
Finally, the ratio of the square to the circle, in area, will be
(2/sqrt(2))^2 : pi*(1)^2 = 2 : pi
We can conclude that the white area is about 35%.
ANSWER

EXPLANATION
We want to convert

to improper fraction.
Let us first reduce the fractional part to get;

We now multiply 6 by 18 and add 5 and then express the result over 18.
This will give us;


