Maths Olympiad Prep

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, 2025

Algebra Difficulty 2.5 Junior Find the answer Canada

At Doggy Daycare, there is one dog for every bowl of food, two
dogs for every bowl of water, and three dogs for every bowl of treats.
Every dog gets a serving of food, water and treats. If there are a total
of 7777 bowls, how many dogs are
there?

Pick one

Solution

There is 11 dog for every
bowl of food, and so if there were 66 dogs, then there would be 66 bowls of food.

There are 22 dogs for every bowl of
water, and so these same 66 dogs
would need 62=3\frac{6}{2}=3 bowls of
water.

There are 33 dogs for every bowl of
treats, and so the 66 dogs would
need 63=2\frac{6}{3}=2 bowls of
treats.

Thus, 66 dogs require 66 bowls of food, 33 bowls of water, and 22 bowls of treats, or 6+3+2=116+3+2=11 bowls in total.

There are 1111 bowls for every 66 dogs, and since there are 77=11×777=11\times7 bowls, then there are 77 groups of 66 dogs, or 6×7=426\times7=42 dogs.

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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.