Question 920351
Total no of person  = 26 
 every person has to meet the other person only once. 
so every shake hand consist of one possible combination
 total no of combinations that can be possible with  26 people  = 26  c 2
                                                              =(26*25)/(2*1)
                                                              =13*25
                                                              =325
 so, total no of shake hands occur  =325