Unit 7 · Data and Percentage

Meeting Vote — How Many Chose the Movie?

Lesson 6 of 9

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About this lesson

21 people vote on 5 movies. Kate says the winner needs at least 5 votes. Samira says 11 votes is a guaranteed win. To check Kate, you need to prove it's impossible for all movies to get 4 or fewer votes — a classic pigeonhole argument.

Chapters

0:00Introduction
0:23Question
1:08Strategy
1:45Step 1: Understand the setup
2:11Step 2: Check Kate — minimum winner votes
2:44Step 3: Check Samira — pick the answer
3:33Correct answer

Question

At the start of the meeting, every member of the movie club gets one vote on the movie to be watched. Everyone must use their vote. The movie that gets the most votes is the one that is watched that evening.

This evening, there are 21 people at the meeting, and there are 5 movies to choose from.

Kate: "The movie that we watch will need to get at least 5 votes."

Samira: "If a movie gets 11 votes then we will definitely be watching it."

If the information in the box is true, whose reasoning is correct?

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