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bixtya [17]
3 years ago
6

"There are 15 questions on an exam. In how many ways can the exam be answered with exactly 8 answers correct?"

Mathematics
1 answer:
erastovalidia [21]3 years ago
5 0

Answer:

The exam can be answered with exactly 8 answers correct in 6435 ways.

Step-by-step explanation:

The order is not important.

For example, answering correctly the questions 1,2,3,4,5,6,7,8 is the same outcome as answering 2,1,3,4,5,6,7,8. So we use the combinations formula to solve this problem.

Combinations formula:

C_{n,x} is the number of different combinations of x objects from a set of n elements, given by the following formula.

C_{n,x} = \frac{n!}{x!(n-x)!}

"There are 15 questions on an exam. In how many ways can the exam be answered with exactly 8 answers correct?"

Combinations of 8 questions from a set of 15. So

C_{15,8} = \frac{15!}{8!(15-8)!} = 6435

The exam can be answered with exactly 8 answers correct in 6435 ways.

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jeka57 [31]

Answer:

The equation is self explanatory, its not asking for a question just giving an example.

Step-by-step explanation:

3 0
4 years ago
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ella [17]
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4 years ago
the slope of line PQ is m= 1/4. find the equation of the line that is parallel to line PQ and that has the y intercept b= -3
nevsk [136]
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 Where,
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