In a college a chess competition has been organized. Every student had to play exactly one game with every other student. It was found that in 45 games both the players were girls. And in 190 games both were boys. The number of games in which one player was a boy and the other was a girl is?
Answers
Answered by
2
Given:
Every student had to play exactly one game with every other student.
It was found that in 45 games both the players were girls.
And in 190 games both were boys.
To find:
The number of games in which one player was a boy and the other was a girl is?
Solution:
Let the total number of girls = g
Let the total number of boys = b
Number of games in which both players were girls = 45
gC2 = 45
[ g(g - 1) ]/2 = 45
g(g - 1) = 90
g = 10
Number of games in which both players were boys = 190
bC2 = 190
[ b(b - 1) ]/2 = 190
b(b - 1) = 380
b = 20
Total number of girls = 10
Total number of boys = 20
Therefore, the number of games in which one person was a boy and other person was a girl
= 20C1 × 10C1
= 20 × 10
= 200
Similar questions