All categories

3 years ago

Find the number of all 20 digit integers in which no two consecutive digits are the same

1 answer:

5 0

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>

You might be interested in

Simplify the expression:<br><br> 5(–5 + 3u) =

Minchanka [31]

Answer:

-25+15u

Step-by-step explanation:

all you need to do is distribute the 5 to everything in the parenthesis!

6 0

2 years ago

Read 2 more answers

Consider the following hypothesis test:

Gnom [1K]

Answer:

a. z=3.09. Yes, it can be concluded that the population mean is greater than 50.

b. z=1.24. No, it can not be concluded that the population mean is greater than 50.

c. z=2.22. Yes, it can be concluded that the population mean is greater than 50.

Step-by-step explanation:

We have a hypothesis test for the mean, with the hypothesis:

$H_0: \mu\leq50\\\\H_a:\mu> 50$

The sample size is n=55 and the population standard deviation is 6.

The significance level is 0.05.

We can calculate the standard error as:

$\sigma_M=\dfrac{\sigma}{\sqrt{n}}=\dfrac{6}{\sqrt{55}}=0.809$

For a significance level of 0.05, the critical value for z is zc=1.644. If the test statistic is bigger than 1.644, the null hypothesis is rejected.

a. If the sample mean is M=52.5, the test statistic is:

$z=\dfrac{M-\mu}{\sigma_M}=\dfrac{52.5-50}{0.809}=\dfrac{2.5}{0.809}=3.09$

The null hypothesis is rejected, as z>zc and falls in the rejection region.

b. If the sample mean is M=51, the test statistic is:

$z=\dfrac{M-\mu}{\sigma_M}=\dfrac{51-50}{0.809}=\dfrac{1}{0.809}=1.24$

The null hypothesis failed to be rejected, as z<zc and falls in the acceptance region.

c. If the sample mean is M=51.8, the test statistic is:

$z=\dfrac{M-\mu}{\sigma_M}=\dfrac{51.8-50}{0.809}=\dfrac{1.8}{0.809}=2.22$

The null hypothesis is rejected, as z>zc and falls in the rejection region.

8 0

3 years ago

An independent-measures research study uses a total of 18 participants to compare two treatment conditions. If the results are u

Luba_88 [7]

Answer:

The answer is false

Step-by-step explanation:

In a sample above 30 obs like this the confidence interval is defined as

X+- t* (s/sqrt(n)) where X is the mean t the tvalue for a given confidence level, n the size of sample and s standar deviation.

To find de appropiate value of t we must see the T table where rows are degrees of freedom and columns significance level

The significance is obtained:

significance = 1 - confidence level = 1 - 0.9 = 0.10

Degrees of freedom (df) for the inteval are

df = n - 1 = 18 - 1 = 17

So we must look for the value of a t with 17 values and significance of 0.10 which in t table is 1.740 not 1.746 ( thats the t for 16 df)

6 0

3 years ago

Which relation is a function?

Degger [83]

Answer: Id say C.

Step-by-step explanation: The other two can't possibly be a function.

<h2><em>Mark as brainliest if im correct please</em></h2>

5 0

2 years ago

A square has a area of 466.56m squared work out the peremiter

MissTica

Answer:

Perimeter = 86.4 (m)

Step-by-step explanation:

A square (with side x) has an area of 466.56 (m^2)

=> x^2 = 466.56

=> x = sqrt(466.56) = 21.6

=> Perimeter of this square: P = 4(x) = 4(21.6) = 86.4 (m)

Hope this helps!

3 0

2 years ago