At the Lomonosov tournament at the MINIMO institute, there were competitions in mathematics, physics, chemistry, biology, and ballroom dancing. When the tournament ended, it turned out that an odd number of schoolchildren participated in each competition, and each schoolchild participated in an odd number of competitions. Was the number of schoolchildren who came to the tournament at MINIMO even or odd?

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Let's consider the sum of the number of participants in all five competitions. This sum is odd, as an odd number of schoolchildren participated in each competition.

On the other hand, this number can also be obtained by summing the number of competitions each schoolchild participated in. Since the sum is odd and all the addends are odd, the number of addends must be odd.

## Answer

Odd