Maths Olympiad Prep

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Algebra Difficulty 2.7 Junior Find the answer Canada

In Jen’s baseball league, each team plays exactly 6 games against each of the other teams in the league. If a total of 396 games are played, how many teams are in the league?

Pick one

Solution

We begin by separating the given information, as follows:

Kathy owns more cats than Alice
Kathy owns more dogs than Bruce
Alice owns more dogs than Kathy
Bruce owns more cats than Alice

From bullets 2 and 3, we can conclude that Alice owns more dogs than both Kathy and Bruce.

From bullet 4, we can conclude that answer (A) is not true.

From bullets 1 and 4, we can conclude that both Kathy and Bruce own more cats than Alice.

However, we cannot determine if Kathy owns more cats than Bruce, or vice versa.

Therefore, we cannot conclude that (B) or (C) must be true.

From bullet 2, we can conclude that (E) is not true.

Thus the statement which must be true is (D).

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Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.