Answer:
180 x 60 inches
Width = 60 inches
Length = 180 inches
Explanation:
Given
Let L = Length
W = Width
P = Perimeter
Length = 3 * Width
L = 3W
Perimeter of Brass = 480 inches
P = 480
Perimeter is given as 2(L + W);
So, 2 (L + W) = 480
L + W = 480/2
L + W = 240
Substitute 3W for L; so,
3W + W = 240
4W = 240
W = 240/4
W = 60 inches
L = 3W
L = 3 * 60
L = 180 inches
Answer: LED have the lowest cost of operation.
Explanation:
If we ignore the initial procurement cost of the items the operational cost of any device consuming electricity is given by

Among the three item's LED consumes the lowest power to give the same level of brightness as compared to the other 2 item's thus LED's shall have the lowest operational cost.
Answer:
a) The final equilibrium temperature is 83.23°F
b) The entropy production within the system is 1.9 Btu/°R
Explanation:
See attached workings