There were two women participating in a chess tournament. Every partic...
Let there be n men participants. Then, the number of games that the men play between themselves is 2. nC2 and the number of games that the men played with the women is 2.(2n)
∴ 2nC2 − 2⋅2n = 66 (given)
⇒ n (n−1) − 4n − 66 = 0
⇒ n2 − 5n − 66 = 0
⇒(n + 5) (n − 11) = 0
⇒ n = 11
∴ Number of participants =11 men+2 women=13
There were two women participating in a chess tournament. Every partic...
Given information:
- There were two women participating in a chess tournament.
- Every participant played two games with the other participants.
- The number of games that the men played between themselves exceeded by 66 the number of games that the men played with the women.
Let's assume:
- The number of men participating in the tournament is 'x'.
- The total number of participants, including men and women, is 'y'.
Number of games played:
- Each participant plays two games with every other participant.
- The total number of games played will be the sum of all pairwise combinations of participants.
Number of games played between men:
- Since there are 'x' men participating, the number of games played between men can be calculated using the combination formula: C(x, 2) = x(x-1)/2.
Number of games played between men and women:
- Since there are 'x' men and 2 women participating, the number of games played between men and women can be calculated using the multiplication principle as x * 2.
Given condition:
- The number of games played between men exceeds by 66 the number of games played between men and women.
- Mathematically, it can be represented as: x(x-1)/2 = x * 2 + 66.
Solving the equation:
- Simplifying the equation, we get x(x-1)/2 - x * 2 = 66.
- Expanding the equation, we get x^2 - x - 4x = 132.
- Combining like terms, we get x^2 - 5x - 132 = 0.
- Factoring the quadratic equation, we get (x - 11)(x + 12) = 0.
- Solving for 'x', we get x = 11.
Number of participants:
- The total number of participants, including men and women, is 'y'.
- Since there are 2 women participating, the total number of participants will be 11 (x) + 2 = 13.
Conclusion:
The correct answer is option 'C', i.e., 13 participants.
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