A group of 100 people plays carrom, snooker and chess. 90 people play chess, 80 people play snooker and 80 people play carom. Find the maximum number of people who play all 3 games, if each person plays at least one game.
75
S= 90+80+80=250
X= 100
Using the Maxima of all shortcut
S−XN−1=1502=75