<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
Find out the value of x.
To prove
By using the trignometric identity

As given in the diagram.

Perpendicular = x
Hypotenuse = 6
Put in the above identity


Put in the above

x = 4.6 cm (Approx)
Therefore Option (c) is correct .
Answer: 
Step-by-step explanation:
The formula for finding the nth term of an arithmetic sequence is given as:

first term = -15
common difference = -6 - (-15) = 9
number of terms
substituting into the formula , we have :


Answer:
4(a+b)
Step-by-step explanation:
Answer: (B) x^3
Explanation:
If you compare the graphs of
all on the interval -1 < x < 0, you'll find that y = x^3 is the smallest when x = -1
Squaring a negative number leads to a positive result, and similarly that happens with x^4 as well. This is because x^4 = (x^2)^2.
Plugging x = -1 into x^3 leads to y = -1 as a result.