Solution
We have the following info:
In-line Roller skates Total
Age 8 4 2 6
Age 10 5 3 8
__________________________________
Total 9 5 14
For this case we can define the following events:
A= the skater belong roller skates
B= the skate is at age 8
And we want to find this probability:

And we can do this:
P(A and B) = 2/14
P(B)= 6/14
Replacing we got:
