Answer:
Maximum volume of the box will be 7.41 cubic feet.
Step-by-step explanation:
Open box has been made from a metal sheet measuring 3 ft and 8 ft.
Let four square pieces were removed from the four corners with one side measurement x ft.
Volume of the open box = Length × width × height
Length of the box = (3 - 2x) ft
Width of the box = (8 - 2x) ft
Height of the box = x ft
Volume of the box = (3 - 2x)(8 - 2x)x
V = (24 - 6x - 16x + 4x²)x
V = 24x - 22x² + 4x³
Now we take the derivative of V with respect to x and equate the derivative to zero,
V' = 24 - 44x + 12x²
V' = 0
12x² - 44x + 24 = 0
3x² - 11x + 6 = 0
3x² - 9x - 2x + 6 = 0
3x(x - 3) - 2(x - 3) = 0
(3x - 2)(x - 3) = 0
(3x - 2) = 0
and (x - 3) = 0
Therefore, x = 3, 
For x = 0.67
Length of the box = (3 - 2x) = 3 - 1.34
= 1.66 ft
Width of the box = (8 - 2x) = 8 - 1.34
= 6.66 ft
Volume of the box = 0.67 × 1.66 × 6.66
V = 7.41 cubic feet.
Similarly, for x = 3,
Length of the box = (3 - 2\times 3) = -3
which is negative but the length of the box can not be negative.
Therefore, maximum volume of the box will be 7.41 cubic feet.
Answer:
A). Surface area = 222 cm²
Volume = 180 cm³
B). Surface area = 375 cm²
Volume = 360 cm³
C). % increase in surface area = 67.57%
% increase in volume = 100%
Step-by-step explanation:
In the figure attached base of a prism has been given.
A). Surface area of the prism = (Perimeter of the base of the prism) × height + 2(area of the base)
Perimeter of the base = 5 + 3 + 2 + 2 + 2 + 3 + 5 + 8
= 30
Area of the base = 8×5 - 2×2 = 36 cm²
Surface area of the prism = 30×5 + 2×(36)= 222 cm²
Volume of the prism = volume of the bigger prism - volume of the smaller prism cut off
= 8×5×5 - 2×2×5
= 200 - 20
= 180 cm³
B). Surface area of the prism if it's height is 10 cm,
Surface area = 30×10 + 2×(36) = 372 cm²
Volume of the prism = 8×5×10 - 2×2×10
= 400 - 40
= 360 cm³
C). Increase in surface area = 372 - 222 = 150 cm²
% increase in the surface area = 
= 67.57%
Increase in volume = 360 - 180 = 180 cm³
% increase in volume = 
= 100%
Answer:
You have to take 15 pens to get at least one red pencil.
Step-by-step explanation:
If there were one red and 6 green pens, there would be more red than green pens.
If there were 3 or more blue and thus 18 or more green pens, the number of pens would be over 20.
So there must be 2 blue, 12 green and thus 6 red pencils. So you have to take at least 15 pens to be sure that you got a red one.
Answer:
agidls
Step-by-step explanation:
Answer: x=3/2
Step-by-step explanation:
