If at the end of certain meeting, everyone had shaken hands with everyone else, it was found that 45 handshakes were exchanged, then the number of members present at the meeting, are

Step-by-step solution

Let ' n ' be the number of members in the meeting Total number of handshakes = ^ n C ₂ ^ n C ₂=45 array ll & n ! 2 !( n -2) ! =45 & n ( n -1)( n -2) ! 2 ( n -2) ! =45 & n ( n -1)=90 & n ^2- n -90=0 & n =10 or n =-9 (not possible) & n =10 array