[susandixon]

What is the probability of rolling a 7 twice in two rolls of a pair of dice? I was told the answer is 1/36, but I don't know how to get that answer.

[gevatter]

One dice has 6 faces... so two dices has 36(6*6) faces

so the probability to roll a 7 is 1/36

two 7 in a row: 36*36 = 1296

so the probability to roll two 7 in a row is 1/1296

[ojasdoshi]

Since a dice does not have a face '7', it is impossible to get 7 on the face. Since the event is impossible, the probability should be 0.

[ebaines]

Unfortunately neither of the first two answers are correct. When you roll two die there are 6 x 6 = 36 possible combinations of results. Six of those 36 result in a total of 7; they are 1+6, 2+5, 3+4, 4+3, 5+2, and 6+1. So the probability of rolling a 7 with a pair of die is 1/6. Now to get 7 twice in a row requires getting a 7 on the first roll and getting 7 on the second - the probability of both things occurring is 1/6 x 1/6 = 1/36.