You draw two cards at random from a standard deck. what is the probability of drawing at least one diamond?

Total number of cards in a deck = 52
Total number of diamond cards =13

Possible favourable outcomes:
1. The first card is a diamond but the second card is not.
2. The first card is not a diamond but the second card is.
3. Both the first and second cards are diamonds.

P(at least one diamond card) = (13/52) (39/51) + (39/52) (13/51) + (13/52) (12/51) = 15/34

15/34