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Mrs. Reid is going on a trip. She has 9 books that she hasn't read yet, but she wants to bring only 3 on the trip. In how many ways can she choose 3 books to bring on the trip?

♦27
♦84
♦504
♦60,480

1 Answer

3 votes

Answer:

Option B is right.

Explanation:

Given that there are totally 9 books unread by Mrs. Reid. OUt of these she wants to take only 3 books on the trip.

For books order does not count.

Hence combinations would be appropriate to calculate.

3 books out of 9 can be selected in

9C 3 ways

No of ways of selecting 3 books for the trip out of 9 =
(9(8)(7))/(1(2)(3)) =84

There are just 84 ways of choosing 3 books to bring on the trip out of 9 unread books.

Option B is right.

User Alan Wagner
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