Each of the letters in the word PLOTTING are on separate cards, face down on the table. If you pick

Each of the letters in the word PLOTTING are on separate cards, face down on the table. If you pick a card at random, what is the probability that its letter will be T or G?

PLOTTING has to 8 letters. It has 2 T'sand 1 G, so we have:
P(T or G) = P(T) + P(G)
P(T or G) = 2/8 + 1/8
P(T or G) = 3/8