C. Is try correct answer
See example in the attached picture
The cost of meal = 
The tip to the waiter =
%
Discount =
%
Cost = 
Cost = 
Cost = $
0
V: volume of a cone = (πr²h)/3 = 104.67 in³
π: pi = 3.14
r: radius = 1/2 diameter = [unknown]
h: height = 4 in
V = (πr²h)/3
V = r²(πh)/3
r² = (3V)/(πh)
r² = (3 ×104.67)/(3.14 × 4)
r² = 25
r = √25
r = 5 (but remember the radius is only 1/2 the diameter)
thus . . .
<u><em>d = 10 in </em></u>
X= 25
Explanation:
The two lines are equal. Since 48+16= 64,
the other line has to equal 64 as well.
64-39= 25