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In a team every player shakes his hand with other player only once. If total number of handshakes is 120, then the number of players is:

Solution

✅ Correct Option: 1

When each player shakes hands with every other player exactly once, the total number of handshakes can be calculated using the combination formula.

For nn players, each player shakes hands with (n−1)(n-1) other players. However, this counts each handshake twice (once for each person involved), so the total is divided by 2.

Number of handshakes =n(n−1)2= \dfrac{n(n-1)}{2}


Given that the total number of handshakes is 120:

n(n−1)2=120\dfrac{n(n-1)}{2} = 120

n(n−1)=240n(n-1) = 240

n2−n=240n^2 - n = 240

n2−n−240=0n^2 - n - 240 = 0


Factoring the quadratic equation, we need two numbers that multiply to −240-240 and add to −1-1.

These numbers are 1616 and −15-15.

(n−16)(n+15)=0(n - 16)(n + 15) = 0

n=16n = 16 or n=−15n = -15


Since the number of players must be positive, n=16n = 16.

Therefore, the number of players is 16.

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