we know that
For a spherical planet of radius r, the volume V and the surface area SA is equal to

The
ratio of these two quantities may be written as

we know


therefore
the answer is

C) 250 is the right answer
You must multiply each number for example 8*4*2= 64 so the after math is 64 after all the work the answer is ^4.
The answer of your problem is C. Because 25 and 100 are related integers.
13 + 5 = 18
The diagram is below
*************+*****=******************