Q31. 
After every gettogether every person present shakes the hand of every other person. If there were $105$ handshakes in all, how many persons were present in the party? 
A.  14 

B.  13 

C.  15 

D.  16 
Q35. 
In a railway compartment, there are $2$ rows of seats facing each other with accommodation for $5$ in each, $4$ wish to sit facing forward and $3$ facing towards the rear while $3$ others are indifferent. In how many ways can the $10$ passengers be seated? 
A.  $172,000$ 

B.  $12,600$ 

C.  $45,920$ 

D.  $43,200$ 