SOLUTION: This word problem is on combinations.. How many ways can a student select five questions from an exam containing nine questions?How many ways are there if he must answer the first

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Question 266012: This word problem is on combinations..
How many ways can a student select five questions from an exam containing nine questions?How many ways are there if he must answer the first question and the last question?
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
This word problem is on combinations..
How many ways can a student select five questions from an exam containing nine questions?
`
9 choose 5
`
The combinations of 9 things taken 5 at a time
`
9%21%2F%285%21%289-5%29%21%29=362880%2F%28%28120%29%2824%29%29=362880%2F2880=126
`
How many ways are there if he must answer the first question and the last question?
`
Then there is no choice for 2 of the 5, so the only selections which
can be made for the remaining 3 are from the remaining 7. So it's
`
7 choose 3
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the combinations of 7 things taken 3 at a time:
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7%21%2F%283%21%287-3%29%21%29=5040%2F%28%286%29%2824%29%29=5040%2F144=35
`
Edwin