A deck of cards contains 30 cards with labels 1, 2, . . . , 30. Suppose that somebody is randomly dealt a set of 7 cards of these cards (numbered with seven distinct
numbers).
a) Find the probability that 3 of the cards contain odd numbers and 4 contain even
numbers.
b) Find the probability each of the numbers on the seven cards ends with a different
digit. (For example, the cards could be 3, 5, 14, 16, 22, 29, 30.)