Suppose we want to choose 3 letters, without replacement, from the 4 letters A, B, C, and D. (a) How many ways can this be done, if the order of the choices is relevant?

(b) How many ways can this be done, if the order of the choices is not relevant?

arithmetic sequence

step-by-step explanation:

given that a sequence has terms as

19, 15, 11,

this is represented on a graph

the pattern indicates that the sequence is an arithmetic sequence with i term

a=19 and common difference d =-4

any general term

thus the sequence is reduced by 4 for each successive term starting from 1 and nth term is

24-5n.

first negative term would start after 5th term

5th term =24-25< 0

from 5th term onwards the sequence would be negative.

answer: the first one

step-by-step explanation: use a calculator and divide the minutes by the dollars.

24 units

step-by-step explanation:

mean, 40.6

step-by-step explanation: