I Need the answer to these 7th grade math questions?

Question

its about permutations.

1. P(9,4)

2.P(9,2)

3.P(7,7)

4.P(12,4)

5.P(100,3)

6.5!

forget about the top now answer these
Its about combinations

7. C(6,3)

8. C(8,7)

9. C(10,4)

10. C(20,3)


PLEASE

Answer 1

For example, if we have a total of 10 elements, the integers {1, 2, ..., 10}, a permutation of three elements from this set is (5, 3, 4). In this case, n = 10 and r = 3. To find out how many unique sequences, such as the one previously, we can find, we need to calculate P(10,3) = 720.

An easier way to compute this is to take the first r numbers of n factorial; in this case: take the first 3 numbers in 10 factorial, so you would have 10 times 9 times 8, which equalls 720.

1. P(9, 4) = 9*8*7*6 = 3024
2. P(9, 2) = 9*8 = 72
3. P(7,7) = 7! = 7*6*5*4*3*2*1 = 5040
4. P(12,4) = 12*11*10*9 = 11880
5. P(100, 3) = 100*99*98 = 970200
6. 5! = 5*4*3*2*1 = 120

Answer 2

i have the answer to #6 hehe its 120 =)