There are 16 total "letter cards" (1 ace and 3 face cards per suit), so the probability of drawing a letter card is 16/52 = 4/13.
There are 52 - 16 = 36 non-letter cards, with probability 36/52 = 9/13 of being drawn.
Then the odds of drawing a letter card is the ratio of these probabilities,
(4/13) / (9/13) = 4/9 ≈ 44%