ketkoag wrote:If each of the 12 teams participating in a certain tournament plays exactly one game
with each of the other teams, how many games will be played?
A. 144 B. 132 C. 66 D. 33 E. 23
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No. of ways in which 12th team can play uniquely only once is 11
No. of ways in which 11th team can play uniquely only once is 10
.
.
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No. of ways in which 2nd team can play uniquely only once is 1
=> Total no. of ways are 11+10+9+8+7+6+5+4+3+2+1 = 11*12/2 = 66 ways.
Thus, C
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Please correct if wrong.