Maths Olympiad Prep

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, 2015

Algebra Difficulty 1.4 Junior Find the answer Canada

Jim wrote the sequence of symbols \heartsuit\,\spadesuit\,\spadesuit\,\heartsuit\,\diamondsuit\,\heartsuit\,\heartsuit\,\heartsuit\,\diamondsuit a total of 50 times. How many more \heartsuit symbols than \spadesuit symbols did he write?

Pick one

Solution

Solution 1

The sequence of symbols includes 5 \heartsuit’s and 2 \spadesuit’s.

This means that, each time the sequence is written, there are 52=35-2=3 more \heartsuit’s written than \spadesuit’s.

When the sequence is written 50 times, in total there are 503=15050 \cdot 3 = 150 more \heartsuit’s written than \spadesuit’s.

Solution 2

The sequence of symbols includes 5 \heartsuit’s and 2 \spadesuit’s.

When the sequence is written 50 times, there will be a total of 505=25050 \cdot 5 = 250 \heartsuit’s written and a total of 502=10050 \cdot 2 = 100 \spadesuit’s written.

This means that there are 250100=150250-100 = 150 more \heartsuit’s written than \spadesuit’s.

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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.