[計量] 一題關於機率的數學
題目是這樣的
The 4 beads in a bag are identical except that 2 are red
and 2 are blue. If 2 beads are to be simultaneously and
randomly selected, what is the probability that they will
both be BLUE?
A. 1/6
B. 1/4
c. 1/3
D. 1/2
E. 5/6
以下是我的想法
2/C4取2 =1/3
兩顆藍的/4顆中挑兩顆
請大家告訴我我漏了什麼?????
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