There are 20 students in the class.
3x²-11=x+13
3x²-x-24=0
(3x+8)(x-3)=0
x=3 or -8/3
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Answer:
The pressure is changing at 
Step-by-step explanation:
Suppose we have two quantities, which are connected to each other and both changing with time. A related rate problem is a problem in which we know the rate of change of one of the quantities and want to find the rate of change of the other quantity.
We know that the volume is decreasing at the rate of
and we want to find at what rate is the pressure changing.
The equation that model this situation is

Differentiate both sides with respect to time t.

The Product rule tells us how to differentiate expressions that are the product of two other, more basic, expressions:

Apply this rule to our expression we get

Solve for 

when P = 23 kg/cm2, V = 35 cm3, and
this becomes

The pressure is changing at
.
Division of two quantities is expressed as the quotient of those two quantities.
The word quotient is derived from the Latin language. It is from the Latin word "quotiens" which means "how many times." A quotient is the answer to a divisional problem. A divisional problem describes how many times a number will go into another. The first time that this word was known to have been used in mathematics was around 1400 - 1500 AD in England.
There are two different ways to find the quotient of two numbers. One of them is through Fractions. The quotient of a fraction is the number obtained when the fraction is simplified. The other way to find a quotient is by employing the long division method where the quotient value is positioned above the divisor and dividend.
You can see that there are 6 rock CDs, over a total of

So, the ratio of rock CDs over the total number of CDs is

Which is 15%.
So, yes, the answer is A