The <em>total</em> area of all six faces of the tunnel is 
square centimeters.
<h2>Procedure - Surface area of a tunnel for a toy train</h2>
The surface area of the solid (
) used to represent the tunnel for a toy train is the sum of its six faces (two <em>semicircular</em> sections, inner <em>semicircular</em> arc section, outer <em>semicircular</em> arc section, two rectangles).
<h3>Determination of the surface area of the tunnel based on information of the diagram</h3>
We calculate the surface area as following:
![A = 2\cdot \frac{\pi}{2} \cdot [(10\,cm)^{2}-(8\,cm)^{2}] + \pi\cdot (8\,cm)\cdot (30\,cm) + \pi\cdot (10\,cm)\cdot (30\,cm) + 2\cdot (2\,cm)\cdot (30\,cm)](https://tex.z-dn.net/?f=A%20%3D%202%5Ccdot%20%5Cfrac%7B%5Cpi%7D%7B2%7D%20%5Ccdot%20%5B%2810%5C%2Ccm%29%5E%7B2%7D-%288%5C%2Ccm%29%5E%7B2%7D%5D%20%2B%20%5Cpi%5Ccdot%20%288%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29%20%2B%20%5Cpi%5Ccdot%20%2810%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29%20%2B%202%5Ccdot%20%282%5C%2Ccm%29%5Ccdot%20%2830%5C%2Ccm%29)
The <em>total</em> area of all six faces of the tunnel is square centimeters. 
To learn more on surface areas, we kindly invite to check this verified question: brainly.com/question/2835293
Answer:
Step-by-step explanation:
<u>Let the number be x</u>
- 380% of x is 99
- x*3.8 = 99
- x = 99/3.8
- x = 26 rounded to the nearest whole number
Actual cost of the TV = $175.95
Percentage of discount given on the TV = 20%
Then
Amount of discount on the TV = (20/100) * 175.95 dollars
= 175.95/5 dollars
= 35.19 dollars
So cost of the TV after discount = (175.95 - 35.19) dollars
= 140.76 dollars
Now
Percentage of sales tax that needs to be added = 6%
Then
Amount of sales tax that needs to be added = (6/100) * 140.76 dollars
= 844.56/100 dollars
= 8.45 dollars
Then
Price of TV after adding sales tax = (140.76 + 8.45) dollars
= 149.21 dollars
So the cost of the TV after deducting the discount and adding the sales tax is $149.21
