Final answer:
The probability of both dice rolling a six given that at least one die rolled a six is 1/5.
Step-by-step explanation:
The probability that both dice rolled a six can be calculated using conditional probability. Let's assume that one die rolls a six. There are 5 other possible outcomes for the second die (1, 2, 3, 4, 5), out of which only 1 is a six. So the probability of rolling a six on the second die given that at least one die rolled a six is 1/5. Therefore, the answer is 1/5.