Find the theoretical probability of the event when rolling a 12-sided dice p(11)

What is the length of bc ? enter your answer in the box.bc =

In simplified exponential notation, the expression a^2•a^-3•a 1/a 0

What are the relative frequencies, to the nearest hundredth, of the rows of the two-way table? group 1: a 15 b 45 group 2: a 20 b 25