A party of tourists booked a room in a hotel for $ 120. Three of the members failed to pay, as a result, other had to pay $ 2 more. How many gentlemen were there in the party ?

Seven relatives of a man comprises four ladies and three gentlemen: his wife has also seven relatives-three of them are ladies and four gentlemen. In how many ways can they invite 3 ladies and 3 gentlemen at a dinner party so that there are three mans relatives and three wifes relatives?