Question

A compound experiment consists of drawing at random twice without replacing from a jar with 3 red, 3 white, and 2 black marbles. What is the probability of getting first a red and then a black marble?
3/28
3/32
1/4

Answer 1

You are drawing at random twice without replacement.

red marbles = 3
white marbles = 3
black marbles = 2

total marbles = 3+3+2 = 8

Probability of first getting a red marble = number of red marbles/ total marbles = 3/8

After removing one red marble,
total marble = 8-1 = 7

Now, probability of getting a black marble = 2/7

Probability of getting first a red and then a black marble = 3/8 × 2/7 = 3/28

Answer is 3/28