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:
-(276÷0.12)=-2300
Step-by-step explanation:
Answer:
y = 3
Step-by-step explanation:
y = (3x² + 3x + 6) / (x² + 1)
The power of the numerator and denominator are equal, so as x approaches infinity, y approaches the ratio of the leading coefficients.
y = 3/1
Answer:
-360
Step-by-step explanation:
b^2-4ac=(-6)^2-4(9)(11)
=36-396
=-360
Answer:
The maximum possible number of mosquitoes is 25 millions
Step-by-step explanation:
Let
m(x) -----> the number of mosquitoes in Minneapolis, Minnesota (in millions of mosquitoes)
x ----> the rainfall in centimeters
we have
This is a quadratic equation (vertical parabola) open downward
The vertex is the maximum
we know that
The maximum possible number of mosquitoes is equal to the y-coordinate of the vertex
Find out the coordinate of the vertex
The general equation of a vertical parabola in vertex form is equal to
where
a is a coefficient
(h,k) is the vertex
so
In this problem
a=-1 (open downward)
(h,k)=(5,25)
The y-coordinate is 25
therefore
The maximum possible number of mosquitoes is 25 millions
