a*******a
发帖数: 1240 | 1 A jar contains 12 red gobstoppers and 8 white gobstoppers. 2 gobstoppers are
taken out randomly (without replacement). what is the probability that they
are of different color?
似乎高中学过，都忘光了。 |
w**********r
发帖数: 986 | 2 12*8/(20*19/2)
are
they
【在 a*******a 的大作中提到】
: A jar contains 12 red gobstoppers and 8 white gobstoppers. 2 gobstoppers are
: taken out randomly (without replacement). what is the probability that they
: are of different color?
: 似乎高中学过，都忘光了。
|
a*******a
发帖数: 1240 | 3 大神能说说是怎么算出来的么？
我智商有限啊。
【在 w**********r 的大作中提到】
: 12*8/(20*19/2)
:
: are
: they
|
m**k
发帖数: 18660 | 4 12/20×8/19+8/20×12/19
are
they
【在 a*******a 的大作中提到】
: A jar contains 12 red gobstoppers and 8 white gobstoppers. 2 gobstoppers are
: taken out randomly (without replacement). what is the probability that they
: are of different color?
: 似乎高中学过，都忘光了。
|
