If the length of each edge of the cube shown in the figure is 8 inches, find the following

In answering a question on a multiple-choice test, a student either knows the correct answer or guesses it. Let 0.7 be the proba

Dahasolnce [82]

Answer:

The probability is 0.9211

Step-by-step explanation:

Let's call K the event that the student know the answer, G the event that the student guess the answer and C the event that the answer is correct.

So, the probability P(K/C) that a student knows the answer to a question, given that she answered it correctly is:

P(K/C)=P(K∩C)/P(C)

Where P(C) = P(K∩C) + P(G∩C)

Then, the probability P(K∩C) that the student know the answer and it is correct is:

P(K∩C) = 0.7

On the other hand, the probability P(G∩C) that the student guess the answer and it is correct is:

P(G∩C) = 0.3*0.2 = 0.06

Because, 0.3 is the probability that the student guess the answer and 0.2 is the probability that the answer is correct given that the student guess the answer.

Therefore, The probability P(C) that the answer is correct is:

P(C) = 0.7 + 0.06 = 0.76

Finally, P(K/C) is:

P(K/C) = 0.7/0.76 = 0.9211

7 0

3 years ago

Is 3,067,952 - -3,469,460 positive or negative?

Irina18 [472]

Answer: positive

Step-by-step explanation:

6 0

1 year ago

Today there are a total of six toll-free area codes: 800, 844, 855, 866, 877, and 888. Assume that all seven digits for the rest

Ludmilka [50]

Answer:

$6 \times 10^{7}$

Step-by-step explanation:

Total number of toll-free area codes = 6

A complete number will be of the form:

800-abc-defg

Where abcdefg can be any 7 numbers from 0 to 9. This holds true for all the 6 area codes.

Finding the possible toll free numbers for one area code and multiplying that by 6 will give use the total number of toll free numbers for all 6 area codes.

Considering: 800-abc-defg

The first number "a" can take any digit from 0 to 9. So there are 10 possibilities for this place. Similarly, the second number can take any digit from 0 to 9, so there are 10 possibilities for this place as well and same goes for all the 7 numbers.

Since, there are 10 possibilities for each of the 7 places, according to the fundamental principle of counting, the total possible toll free numbers for one area code would be:

Possible toll free numbers for 1 area code = 10 x 10 x 10 x 10 x 10 x 10 x 10 = $10^{7}$

Since, there are 6 toll-free are codes in total, the total number of toll-free numbers for all 6 area codes = $6 \times 10^{7}$

4 0

3 years ago

I NEED HELP QUICKLY!! Find the sum of the first 42 terms of the sequences (12, 16, 20, ....)

12345 [234]

Answer:

B

Step-by-step explanation:

Note the common difference between consecutive terms of the sequence.

d = 16 - 12 = 20 - 16 = 4

This indicates the sequence is arithmetic with sum to n terms

$S_{n}$ = $\frac{n}{2}$ [2a₁ + (n - 1)d ]

where a₁ is the first term and d the common difference

Here a₁ = 12 and d = 4, thus

$S_{42}$ = $\frac{42}{2}$ [ (2 × 12) + (41 × 4) ]

= 21( 24 + 164) = 21 × 188 = 3948 → B

7 0

3 years ago

Q2: Explain the difference between the solution to an equation and the solution to an inequality. (dba 3

CaHeK987 [17]

The solution(s) of a system of linear equations give points of intersection of specific lines or planes.

The solution(s) of a system of linear inequalities give areas of intersection wherein any specific pair of points or lines are solutions.

PROCESS-WISE there are little differences between solving systems. However, multiplication and division by negatives reverses the signs in inequalities.

4 0

3 years ago