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:
Im pretty sure the answer is 68, but I could be wrong...
Answer: The radius is half the diameter and the diameter is double the radius
Step-by-step explanation:
The diameter is a straight line across the center of a circle. It goes from one side to another. The radius is half that, so a line starting from the center that goes to just one side.
Answer:
m = 2
n = -4
Step-by-step explanation:
Using elimination method:
4m + n = 4
m - n = 6
--------------------
5m = 10 // n-n = 0, solve for me
m = 10/5 //divide both sides by 5
m = 2
Pick any only of the equation, replace me with it's value.
m - n = 6
2 - n = 6 //subtract 2 on both sides
-n = 6-2
-n = 4 //Change sign, multiply by -1
n = -4
Solution:
m = 2
n = -4
Hope it helps you.ask if anything is not clear