You are given the set of letters { A, B, C, D, E } . How many three-letter strings (i. e., sequences of 3 letters) can be made out of these letters if each letter can be used only once? (In this and subsequent questions, your answer should be a number. Do not enter ‘!' or combinations in your answer.)

60

Step-by-step explanation:

If each letter can be used only once then

- The first slot has a total of 5 options

- The 2nd slot has a total of 4 options

- The 4rd slot has a total of 3 options

Then the total number of combination to arrange 5 letters into 3 slots is

5 * 4 * 3 = 60

22, 28, 34, 40, 46

b)   f(n) = 6n + 16

n = what is the number of the row ( 22 would be row 1) so if we replaced n with 1, we would get 22

c)   the 14th row will have 100 seats

(1)   (2)   (3)   (4)   (5)   (6)   (7)   (8)   (9)   (10) (11) (12) (13) (14)

22 | 28 | 34 | 40 | 46 | 52 | 58 | 64 | 70 | 76 | 82 | 88 | 94 | 100