Let N be the number of items sold and p the price.
Since the variation is inverse, then the relation between N and p is:

For N=20000 and p = $9.5, we get the formula:

If p = 8.75, then the number of items sold can be computed using the formula:
Answer:
Angle
Step-by-step explanation:
Since, the figure is in the final step of construction. So, it will have only two rays which as we can see are emerging from a common point.
So, it represents an angle.
An angle has two rays arising out of a common vertex point.
Let the number of stamps be s and the number of coins be c.
This means that s+c=300 and 3c+1.5s=825.
Multiplying the first equation by 3 yields 3s+3c=900.
Subtracting the second equation from this gives that 1.5s=75, and thus s=50.
It follows that c=250, so there are <u>2</u><u>5</u><u>0</u> coins.
<h3>
Answer: 1 hour</h3>
==================================
Explanation:
In the method I show below, the value 600,000 liters is never used. All that matters are the two values of 100 minutes and 150 minutes.
Pipe A drains the pool in 100 minutes. The rate it drains the pool is 1/100 of a pool per minute. If you multiply 1/100 by 100, then you'll represent 1 full job being done (that job being draining the pool).
Pipe B drains the pool in 150 minutes. Pipe B's rate is 1/150 of a job per minute.
In total, the combined rate is
1/100 + 1/150 = 3/300 + 2/300 = 5/300 = 1/60 of a pool per minute
This means it takes them 60 minutes to drain the pool assuming the two pipes work the most efficiently together (ie one pipe doesn't hinder the other). Since 60 minutes = 1 hour, it's much easier to say it takes 1 hour to drain the pool with both pipes working together.
---------------------------------
We can get this same answer through solving the equation
1/x + 1/y = 1/z
for z. Use x = 100 and y = 150.