A Receptacle contains 3violet, 4purple and 5 black balls. Three balls are drawn at random from the receptacle. The probability that all of them are purple is:
Correct Option is: C Let S be the sample space.
Then, n(S) = number of ways of drawing 3 balls out of 12 = 12C3 = 220
Let E = event of getting all the 3 purple balls.
n(E) = 4C3= 4
P(E) = n(E)/n(S) = 4/220 = 1/55