<span>30 hours
For this problem, going to assume that the actual flow rate for both pipes is constant for the entire duration of either filling or emptying the pool. The pipe to fill the pool I'll consider to have a value of 1/12 while the drain that empties the pool will have a value of 1/20. With those values, the equation that expresses how many hour it will take to fill the pool while the drain is open becomes:
X(1/12 - 1/20) = 1
Now solve for X
X(5/60 - 3/60) = 1
X(2/60) = 1
X(1/30) = 1
X/30 = 1
X = 30
To check the answer, let's see how much water would have been added over 30 hours.
30/12 = 2.5
So 2 and a half pools worth of water would have been added. Now how much would be removed?
30/20 = 1.5
And 1 and half pools worth would have been removed. So the amount left in the pool is
2.5 - 1.5 = 1
And that's exactly the amount needed.</span>
Answer:
(0,-9)
Step-by-step explanation:
The image of a point
over a line
is given by the co-ordinate rule:
→ 
So, when we reflect a point over the line
, the x co-ordinate and y co-ordinate change their places.
Here,
is
. So, from the above rule, after reflection over the line
, the image has the following co-ordinates:

Answer:If you have two parallel lines and shift both to the left by the same amount, that does not alter the distance between the lines. Thus, c is correct.
Step-by-step explanation:
Answer:
b^20/a^12
Step-by-step explanation:
b to the power of 20 over a to the power of 12