PERMUTATION INTERESTING PROBLEM ....?

I'm totally new to this.

A van has 2 rows of 5 seats on each side. 5 married couples get on the van. In how many ways can they be seated if

(a) there is no restriction,

(b) the 5 wives are on the same side,

(c) each husband sits opposite his wife,

(d) each husband sits next to his wife except

(i) one couple (ii) one particular couple

for which, in each case, the husband and the wife sit opposite each other.

PLease frnds give me the good answers.

Next Question

5 married couples queue up to buy tickets for a show. In how many ways can they do so if

(a) there is no restriction

(b) the men queue up behind the women

(c) husband and wife are together.

(d) a man and a woman alternate?

Please explain me clearly.

THANKS