prateekbhatt wrote:
A certain bag of gem stones is composed of 2/3 diamonds and 1/3 rubees, if the probability of selling 2 diamonds from the bag without replacement is 5/12. what is the probability of selecting 2 rubees from the bag without replacement?
A)1/12
B)7/12
C)1/6
D)5/12
E)1/16
A)1/12
B)7/12
C)1/6
D)5/12
E)1/16
.
solution:
probability = 1/3 . (1/3 x - 1)/(x-1) = (x-3)/9(x-1) here, x=6 or 9 applicable, but x=6 doesn't provide an answer.
so x=9. so prob = 6/9.8 = 1/12