Question

A box contains 2 black, 4 white, and 3 red balls. One ball is drawn at random from the box and kept aside. From the remaining balls in the box, another ball is drawn at random and kept aside the first. This process is repeated till all the balls are drawn front the box. The probability that the balls drawn are in the sequence of 2 black, 4 white, and 3 red is `1//1260` b. `1//7560` c. `1//126` d. none of these Select the correct answer from above options

Answer 1

Correct Answer - A::B Since, the drawn balls are in the sequance black, black, white, white, white, white, red, red, and red. Let the corresponding probabilities be `p_(1),p_(2),....,p_(9)` Then,`" "p_(1)=(2)/(9),p_(2)=(1)/(8),p_(3)=(4)/(7),p_(4)=(3)/(6),p_(5)=(2)/(5)` `p_(0)=(1)/(4),p_(7)=(3)/(3),p_(8)=(2)/(2),p_(9)-1` `:." Required probabilitie"` `p_(1).p_(2).p_(3)*...*p_(9)` `=((2)/(9))((1)/(8))((4)/(7))((3)/(6))((2)/(5))((1)/(4))((3)/(3))((2)/(2))(1)=(1)/(1260)`