A jar contains 16 marbles,of which 4 are red,3 are blue,and hte rest are yellow.If 2 marbles are 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
Ans: B
不好意思連發了兩題,看來我對這方面的題目都不大會做
我這題是用C(4,1)*C(3,1)/C(16,1)
所以一直算出來的是1/10
希望大家可以幫幫我的忙,謝謝囉......