Suppose you were asked to multiply the numbers at the right, and you wrote 15,000 as your answer. Without using
pencil and paper to actually multiply the numbers, give a
reason why an answer of 15,000 is not reasonable.

30 students (30 total voters)

Step-by-step explanation:

Let s represent the number of students in the class.  Evan earned 80% of these votes, which came to 24 votes.  Symbolically, we have:

                                                                                                  24 votes

0.80s = 24 votes.  Therefore, s = total number of voters = = 30 voters                                                                                              0.8

The total number of students (voters) in his class was 30.