Question

Srinivasa places the nine labelled balls shown below into a box. Srinivasa then chooses two balls at random, one at a time, from the box. The first ball is not replaced before he chooses the second.

a. Find the probability that the first ball is labelled A.
b. Find the probability that the first ball chosen is labelled A or labelled N.
c. Find the probability that the second ball chosen is labelled A, given that the [2] first ball chosen was labelled N.
d. Find the probability that both balls chosen are labelled N.

Answer 1

The probability of events related to choosing balls from a box is calculated step-by-step.

Step-by-step explanation:

1. a. The probability that the first ball is labelled A is 1/9.
2. b. The probability that the first ball chosen is labelled A or labelled N is 2/9.
3. c. The probability that the second ball chosen is labelled A, given that the first ball chosen was labelled N is 1/8.
4. d. The probability that both balls chosen are labelled N is 4/81.