Answer:
13.7142857143
Step-by-step explanation:
If you need to round then do so, or i will comment the rounded version if needed.
From the given information, a exists jointly proportional to b and c.
then 
Therefore, the value of a exists 2.
<h3>
What is the value of a?</h3>
Given, a exists jointly proportional to b and c.

Taking K as the constant of proportionality.
a = K b c
For b = 8 and c = 9, the value of a = 4
4 = K(8)(9)
4 = 72 K
Dividing the equation by 72, we get

Using the value of K in the equation:

Substitute the values of b = 2 and c = 18, in the above equation

a = 2
Therefore, the value of a exists 2.
To learn more the value of x refers to:
brainly.com/question/11874663
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Answer: 
Step-by-step explanation:
Given
The diameter of a circle is 
So, the radius is 
The circumference is given by 
Insert the values

Thus, the circumference of the circle is
The correct answer is B. cm3
This is saying "centimeters cubed", and is true because you are multiplying 3 dimensions of centimeters, width*length*height, to get the answer. Thus, you are multiplying the numbers <em>and </em>the units. 30*30*25 and cm*cm*cm