If two standard number cubes are rolled 100 times, how would you predict the number of times that a sum of 7 or 11 will be rolled?
Roughly 22 times
We can calculate the odds, on any given role, the chance that a 7 or 11 will come up.
Let's say that one cube is Red and the other Green. We can get a 7 when we get:
and so 6 ways to get a 7.
We can get an 11 when we get:
and so 2 ways.
We have 8 possible ways to get a 7 or 11.
On any given role, there are
To figure out the number of 7 or 11 in 100 roles, we can use a ratio:
and now let's solve for