ANKIT Ques 2 ... hogwarts ..

The land of Hogwarts school of magic is different. The no. of girls and boys are equal . All the boys have two hands, while all the girls have only one {:)} . Dumbledore, the principal of the school arranged a party on new year's eve . According to the wishes of dumbledore all the boys and girls shook hands with everyone else in every possible way (i.e. left to left , right to right , left to right and right to left hand, all handshakes are permissible ) .

Q1. If the total number of handshakes that happened on new year's eve was 100, what is the population of the land ?

Q2. If there were 10 boys and 5 girls then what is the number of handshakes ?

Q3. Next day suddenly 5 death eaters with three hands arrived and again all wished each other including the people present earlier (actual population Q1. ) What is the total no. of handshakes ?

N.B. :
HIDE and post ur solution .. so that all of can try this question out .. i'll reply whether u r correct or not in ur chatbox ... :)

see post # 25