ro86 wrote:

There are 8 teams in a certain league and each team plays each of the other teams exactly once. if each game is played by 2 teams, what is the total number of games played?

1.15

2.16

3.28

4.56

OA is 28

I am not able to understand the explanation given to me in the OG.

The OG has calculated the answer as (8x7)/2.

has the og used some formula to arrive at the answer.

Tho i got the answer through manual counting. can any 1 explain the process used in the OG.

this is nothing but application of direct formulae i.e combination ( if one is aware of this)

the formula is if we are asked to select r items out of n items then we can say nCr=n!/[(n-r)!*(n!)]

now in this q to play a match we need 2(r) teams out of 8(n) teams substituting

we get 8!/[2!*6!]=8*7*6!/[2!*6!]=8*7/2=28

HTH

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