Roll two fair dice separately. Each dice has six faces. Let B be the event that the sum of the two rolls is at most seven. P(B) =

To find the probability of event B, we first need to determine the total number of outcomes when rolling two dice. Since each die has 6 faces, the total number of outcomes is 6*6 = 36.

Next, we need to find the number of outcomes where the sum of the two rolls is at most seven. These outcomes are: (1,1), (1,2), (1,3), (1,4), (1,5), (1,6), (2,1), (2,2), (2,3), (2,4), (2,5), (3,1), (3,2), (3,3), (3,4), (4,1), (4,2), (4,3), (5,1), (5,2), (6,1). This gives us a total of 21 outcomes.

The probability of an event is the number of favorable outcomes divided by the total number of outcomes. Therefore, the probability of event B, P(B), is 21/36 = 0.5833.