Need Combination and Permutation help Please

I need help with my combination and permutation, I really appreciate everyones help!

Tell whether each problem represents a permutation or combination. Then solve the problem.

1. How many ways can you select 4 essay questions out of a total of 10 on an exam?

2. 6 children remain in a game of musical chairs. If 2 chairs are removed, how many different groups of students can remain?

3. How many ways can 3 flute players be seated in the first, second, or third seats in the orchestra?
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4. In how many ways can 4 paintings be displayed from a collection of 15?

5. Given 12 Web sites, how many ways can you visit half of the sites?

Again, I appreciate everyones help. Thank you!

1. How many ways can you select 4 essay questions out of a total of 10 on an exam?

I do not think the order of the questions matters, so ask: how many combinations of 10 unique objects taken 4 at a time are there?

The answer (it is in your book): C(10 4) = 10!/(10 – 4)!/4! = 210

You do not pay enough to do more than one exercise per submission.

1. Combinations : 4 taken out of 10

2. ???

3. Permutations of 3

4.Arangements : 4 out of 15

5.Arangements : 6 out of 12


PS: I hope you understand as my English isn't that good at expressing maths.