A jar contains 16 marbles, of which 4 are red, 3 are blue, and the rest are yellow. If 2 marbles are to be selected at random from the jar, one at a time without being replaced, what is the probability that the first marble selected will be red and the second marble selected will be blue? A. 3/64 B. 1/20 C. 1/16 D. 1/12 E. 1/8 Answer: B 我的算法是4乘3/C16取2=1/10（不知道杂子能打出来，只能这样了，看的懂吧？） | 
(16 2)
