Answer:
The volume of the ball with the drilled hole is:

Step-by-step explanation:
See attached a sketch of the region that is revolved about the y-axis to produce the upper half of the ball. Notice the function y is the equation of a circle centered at the origin with radius 15:

Then we set the integral for the volume by using shell method:

That can be solved by substitution:

The limits of integration also change:
For x=5: 
For x=15: 
So the integral becomes:

If we flip the limits we also get rid of the minus in front, and writing the root as an exponent we get:

Then applying the basic rule we get:

Since that is just half of the solid, we multiply by 2 to get the complete volume:


Answer:
(3, 2)
Step-by-step explanation:
Answer:
Option (a) is correct.
The system of equation becomes

Step-by-step explanation:
Given : Equation 
We have to construct a system of equations that can be used to find the roots of the equation 
Consider the given equation 
To construct a system of equation put both sides of the given equation equal to a same variable.
Let the variable be "y", Then the equation 
becomes,
Thus, The system of equation becomes

Option (a) is correct.
Answer:
9
Step-by-step explanation:
Let the no be x
By the conditions given ,
2x + 6x = 72
8x = 72
x = 72/8
x = 9
therefore the no is 9