A coin is tossed and then a die is rolled. Find the probability of getting a 5 on the die given that the
Coin landed tails up.
A)1/12
B)1/6
C)1/3
D)1/36

Question

Quizplus · Accepted Answer

The fact that the coin landed tails up is a condition or restriction. So we only look at outcomes where the coin is tails. There are 6 possible outcomes for the die to land on 5, but only 3 of them have tails on the coin. Therefore, the probability is 3/18 or simplifying it, 1/6. The probability of getting tails on the coin is 1/2. When the coin lands tails up, there are six equally likely outcomes for the die roll. Only one of these outcomes is a 5. Therefore, the probability of getting a 5 on the die given that the coin landed tails up is 1/6.

A Coin Is Tossed and Then a Die Is Rolled