A passenger aircraft seats 210 passengers in economy class, 7 abreast in rows 30 to 59. All seats are full for the current trip.

The in-flight menu for economy passengers has 3 main-course choices: curried mutton with rice, chicken supreme with brocolli, and pork belly with bean sprouts. Given that, on average, one-third of the passengers will prefer each main-course choice, the aircraft carries 70 meals of each type.

The meals are served from large trolleys that the servers push through the aircraft from row 30 abaft. Each passenger in turn is asked which meal they choose. Naturally, this depends on individual preference, but overall each choice is equally likely. Subject to availability, the passenger is then handed their selection.

Questions:
(1) In what row will at least one main-course choice likely become unavailable?
(2) How many passengers will likely receive a non-preferred meal?