Mathematics for IGCSE & O level - Probability (Section 2 - No. 9)
A fair die is rolled twice. What is the probability of rolling a 3 on the first roll and an even number on the second roll?
1/12
1/3
1/6
1/4
解释
The probability of rolling a 3 on the first roll is 1/6. The probability of rolling an even number (2, 4, or 6) on the second roll is 3/6 = 1/2. The probability of both is (1/6) * (1/2) = 1/12