SOLUTION: A student is to answer 10 out of 13 question in an examination such that he must choose at least 4 from the first five questions.The number of choices available to him is.

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Question 1172276: A student is to answer 10 out of 13 question in an examination such that he must choose at least 4 from the first five questions.The number of choices available to him is.
Found 2 solutions by Solver92311, ikleyn:
Answer by Solver92311(821)   (Show Source): You can put this solution on YOUR website!




You can do your own arithmetic.

John

My calculator said it, I believe it, that settles it

From
I > Ø
Answer by ikleyn(52780)   (Show Source): You can put this solution on YOUR website!
.

First, the student MUST select 4 questions from the first 5 questions.

It can be done in   = 5 ways.



After that, the student is to select 6 questions from remaining 13-4 = 9 question.

He can do it in   =  = 3*4*7 = 84 ways. 



So the answer to the problem's question is  the product  9*84 = 756  ways.

Solved.

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a Post-solution note:

            Notice that my formula is different from that of the post by tutor @Solver92311.




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