Answer:
Part a) The volume of the air is 
Part b) The volume of the plastic is 
Step-by-step explanation:
we know that
The volume of the sphere is equal to

step 1
Find the volume of the complete ball (air +plastic)
we have
------> the radius is half the diameter
substitute


step 2
Find the volume of the air
we have that
The plastic is 2 mm thick
Convert to cm
2 mm=2/10=0.2 cm
so
The radius of the interior of the ball is

substitute

-----> this is the volume of the air (interior of the ball)
step 3
Find the volume of the plastic
we know that
The volume of the plastic is equal to the volume of the complete ball minus the volume of the air
so

The answer is choice B in the upper right hand corner.
Choice B is the graph that is a straight line and it's a single unbroken straight line. There are no gaps or jumps or any kinds of bends like choice A shows. Choice A is an absolute value graph, which is the result of gluing together two linear functions. Overall, graph A is considered nonlinear. Choices C and D are nonlinear as well.
Sent you a pic of the solution to your problem.
Answer:
Total Paperback books = 8x , where x is any positive number
Step-by-step explanation:
Let
The total books are = 13x ; where x is any positive number
As given,
The ratio of hardback books to total books is 5 to 13.
⇒Hardback books =
× Total books
⇒Hardback books =
× 13x = 5x
So, Paperback books = Total books - Hardback books
= 13x - 5x
= 8x
⇒Total Paperback books = 8x