Think of the two pieces together as a single cone of height 19, and its volume.
Then think of only the upper piece as a cone, and find its volume.
The volume of the frustum is the total volume minus the volume of the upper piece.
The volume of a cone is:

Total volume:

Volume of upper cone:

Volume of frustum:
0.05(0.85y)=5%(of the onsale dvd)
and a is just the on sale dvd (85%)
Divide through everything by <em>b</em> :

Since <em>a/b</em> < <em>c/d</em>, it follows that

Multiply through everything on the right side by <em>b/d</em> to get

and so (<em>a</em> + <em>c</em>)/(<em>b</em> + <em>d</em>) < <em>c/d</em>.
For the other side, you can do something similar and divide through everything by <em>d</em> :

and <em>a/b</em> < <em>c/d</em> tells us that

Then

and so (<em>a</em> + <em>c</em>)/(<em>b</em> + <em>d</em>) > <em>a/b</em>.
Then together we get the desired inequality.
Answer:
<u>51.2</u> is 40% of 128
Step-by-step explanation: