Answer:
Its C just got it right.
Step-by-step explanation:
Answer:
Part A:
The surface area of a cylinder is given by
A= 6πr² if h= 2r
Part B:
Total Cost of covering the cylinder = Rate *2πrh + rate*2πr²
Cost of covering only the side = Rate *2πrh
Step-by-step explanation:
Part A:
The surface area of a cylinder is given by
A= 2πrh + 2πr²
Where h= height and radius = r
But we have the height twice as radius so h= 2r
So putting h= 2r we get
A= 2πr(2r) + 2πr²
A= 4πr² + 2πr²= 2πr²(2+1) = 2πr²(3)= 6πr²
Part B:
Cost = Rate * area of the wall + rate * area of the top and bottom
Cost = Rate *2πrh + rate*2πr²
Where area of the top and bottom= πr² +πr² =2 πr²
and area of the side = 2πrh
Multiplying both with the rate and then adding would give the total cost of materials needed to cover the outside of the cylinder and from top and bottom as well.
If you do not need to cover top and bottom then the expression would be
Cost of covering only the side = Rate *2πrh
Part C:
Already done above.
A cube has all sides of equal length.
So let the side be x
that will be length = width = height = x
Now, when we cut the loaf into 5 equal slices, the length and height of the slices are the same as the original loaf. But the width will become less with each slicing. Here the width corresponds to the thickness of the slices.
For each slice the dimensions are -
Length = x
height = x
width = 0.6
Volume of the original loaf is x³.
Volume of 5 slices is 5(x * x * 0.6).
Volume that is left after the cutting the slices is 235 inch³.
So, equation of the volume is=
x³ - 5(0.6x²) = 235
Solve for x using this equation.
x³ - 3x² = 235
x³ - 3x² - 235 = 0
Using a graph calculator to find the roots, we get
x = 7.35
Hence the dimensions of the original loaf is 7.35 inches for each side.
Please find attached the graph.
So you do 20%*426 to get 85.2 then you would subtract 85.2 from 426 because they sold 20% more than last year. On top of that the answer isn't 355 it is 340.8.
