Answer: There are 24336000 different codes that are possible.
Step-by-step explanation:
We know that,
Total alphabets = 26
Total digits = 10
Choices for First place = 26+10=36
Choices for next 3 places = 10 x 10 x 10 = 1000
Choices for last 2 places = 26 x 26 = 676
Total different codes are possible = 36 x 1000 x 676
=24336000
Hence, there are 24336000 different codes that are possible.
Answer:
- north and south sides are 38 8/9 ft long
- east and west sides are 17.5 ft long
Step-by-step explanation:
<u>Short answer</u>: area is maximized when half the cost is spent in each of the orthogonal directions. This means the east and west sides will total $350 at $20 per foot, so will be 17.5 feet. The north and south sides will total $350 at $9 per foot, so will be 38 8/9 feet.
The dimensions that maximize the area are 17.5 ft in the north-south direction by 38 8/9 ft in the east-west direction.
__
<u>Long answer</u>: If x represents the length of the north and south sides, and y represents the length of the east and west sides, then the total cost is ...
10y +10y +2x +7x = 700
9x +20y = 700
y = (700 -9x)/20
We want to maximize the area:
A = xy = x(700 -9x)/20
We can do this by differentiating and setting the derivative to zero:
dA/dx = 700/20 -9x/10 = 0
350 -9x = 0 . . . . multiply by 10
x = 350/9 = 38 8/9
y = (700 -9(350/9))/20 = 350/20 = 17.5
The north and south sides are 38 8/9 ft long; the east and west sides are 17.5 ft long to maximize the area for the given cost.
Answer:
No. 1 , 3 and 5 is correct.
