A pair of dice is tossed. Find the probability that one of the die is 2 if the sum is 6.

To solve this problem, we need to use the concept of conditional probability.

Step 1: Identify the total number of outcomes when two dice are rolled. There are 6 faces on each die, so the total number of outcomes is 6*6 = 36.

Step 2: Identify the outcomes where the sum of the numbers on the two dice is 6. These outcomes are (1,5), (2,4), (3,3), (4,2), and (5,1). So, there are 5 such outcomes.

Step 3: Identify the outcomes where one of the dice shows 2 and the sum is 6. These outcomes are (2,4) and (4,2). So, there are 2 such outcomes.

Step 4: Calculate the probability. The probability that one of the dice shows 2 given that the sum is 6 is the number of outcomes where one die shows 2 and the sum is 6 divided by the total number of outcomes where the sum is 6.

So, the probability is 2/5 = 0.4.