Since you're not returning the marble, there is one less to choose from in the second draw.
First draw: 5/10 (five out of 10 are red)
Second draw: 4/9 (four out of 9).
First AND second draw: 5/10*4/9 = 20/90 = 2/9, answer B.
Second question: the only possibility is to pick a red tulip, so that's a certainty! Answer A.