91影视

Here two balanced dice are rolled.

Let S represent the sample space of the experiments.

\(S = \left\{ \begin{aligned}{}\left( {1,1} \right),\left( {1,2} \right),\left( {1,3} \right),\left( {1,4} \right),\left( {1,5} \right),\left( {1,6} \right)\\\,\left( {2,1} \right),\left( {2,2} \right),\left( {2,3} \right),\left( {2,4} \right),\left( {2,5} \right),\left( {2,6} \right)\\\,\left( {3,1} \right),\left( {3,2} \right),\left( {3,3} \right),\left( {3,4} \right),\left( {3,5} \right),\left( {3,6} \right)\\\,\left( {4,1} \right),\left( {4,2} \right),\left( {4,3} \right),\left( {4,4} \right),\left( {4,5} \right),\left( {4,6} \right)\\\,\left( {5,1} \right),\left( {5,2} \right),\left( {5,3} \right),\left( {5,4} \right),\left( {5,5} \right),\left( {5,6} \right)\\\,\left( {6,1} \right),\left( {6,2} \right),\left( {6,3} \right),\left( {6,4} \right),\left( {6,5} \right),\left( {6,6} \right)\end{aligned} \right\}\)

In the sample space, there are a total of 36 possible outcomes

So the number of outcomes that produces the sum of the two number appear even are 18

\(\begin{aligned}{}\Pr \left( {Sum\,of\,two\,numbers\,appear\,even} \right) &= \frac{{{\bf{Number}}\,{\bf{of}}\,{\bf{Favourable}}\,{\bf{outcomes}}}}{{{\bf{Total}}\,{\bf{outcomes}}}}\\ &= \frac{{18}}{{36}}\\ &= 0.50\end{aligned}\)

So the probability of the sum of two numbers appearing even is 0.50