It can be at least 5.4 feet long since the area of a square is A=s^2. 5.4 times 5.4 is 30
For the first digit of the required 20-digit number, we can have 9 choices for the number, those are the digits 1 to 9. In the second digit of the number, we will only have 8 choices. That is because, we don't want to write a number in the second digit that is similar to the first digit and the third digit.
Similarly, in the third digit's place, we will only have 8 choices because we do not want the digit to be similar to the second digit and the fourth digit. This will go on up until the 19th digit. In the 20th digit, we will also have 9 choices (from 0-9) but we do not want the digit to be similar to the 19th digit.
From the explanation given above, we have the number of ways,
n = 9 x 8^(19 - 1) x 9 = 1.459 x 10^18
<em>ANSWER: 1.459 x 10^18</em>
Answer: 
Step-by-step explanation:
Given:
and 
To find: 
Now as we know

So we have

Therefore d. is the correct option
Hence , 
Answ#$%^&* Im just joking but is that the hole Question thank you
Step-by-step explanation:
Answer:
The problem is stated as:
Min C = 15*(2*x +y) + 21*y
subject to x*y = 450
Step-by-step explanation:
Given that the region is rectangular, it has two opposite sides called x and two other opposite sides called y (both measured in feet). Then, the area (in square feet) is:
A = x*y = 450
One of the sides called y costs $21 per linear foot. The other 3 sides (two x and one y) costs $15 per linear foot. Then, the cost function is:
C = 15*(2*x +y) + 21*y