PROBABILITY please help!!

[ahlashi]

Q) three winning tickets are drawn from an urn containing 100 tickets.
what is the probability of winning if the person buys
1) 4 tickets
2) only 1 ticket



Q2) n how many ways can n people be seated around a table if 2 arrangements are regarded as the same when each person has same left and right neighbour.? At dinner at which n person are seated randomly what is the probability that a specific husband is seated next to his wife ?

[Dr. Strange]

Q1.  When 1 ticket is bought, P(winning)= C(3,1)/C(100,1)
        When 4 tickets are  bought, P(not winning)=C(97,4)/C(100,4)

Q2. IST PART, ANS= (N-1)!/2
 
    2ND PART, P= (((N-2)!/2)  *2)  /  (N-1)!/2   =2/N-1

[Var1995]

 we will apply the same arrangement thing here in this case as well?
we are fixing 2 people here so that's why (n-2) and the multiplication by 2 in the numerator represents the arrangement of husband and wife?

[Dr. Strange]

Yes you are right.