A tourist in a room shakes hands with another person. The total number of handshakes is 45, then...

Every person in a room , shake hands with every other person . The total number of handshakes it 45. The number of person in the room is .

In a party, every person shakes his hand with every other person only once. If total number of handshakes is 210, then find the number of persons.

Twelve persons meet in a room and each shakes hand with all others. Find the number oif hand shakes.

In a function there are 10 men and 8 women. Each man shakes his hand with all the men and each women shakes her hands with all the women. Find the total number of handshakes ?

In a party, there are 10 married couples. Each person shakes hands with every person other than her or his spouse. The total number of handshakes exchanged in that party is ___