Hope this helps :)
Answers:
This can be found by using the combinations and permutations formulas.
Combinations being the C equation and Permutations being the P equation.
21: [tex]C_{6}(21) = \left[\begin{array}{ccc}21\\6\end{array}\right] =\frac{21!}{6!(21-6)!}=\frac{21*20*19*18*17*16}{6*5*4*3*2*1} = 54264[/tex]
answer: 54264
22: [tex]C_{2}(n) = \left[\begin{array}{ccc}n\\2\end{array}\right] =\frac{n!}{2!(n-2)!}= answer[/tex]
answers:
Art: 15
Writing: 21
Technology: 28
23: [tex]P(n,r)=\frac{6!}{(6-6)!}=720[/tex]
answer: 720
Explanation:
A permutation is an act of arranging the objects or numbers in order. Combinations are the way of selecting the objects or numbers from a group of objects or collection, in such a way that the order of the objects does not matter.
