In a deck of 52 playing cards, what is the probability, as a fraction, of drawing a picture card (A, K, Q, and J) that is also a diamond then a card numbered 2-9?

How many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.) how many 3-digit numbers can you write using only digits 1 and 7? (of course, digits can repeat.)