math (algebra 1)
posted by ruth .
Determine the probability of rolling a sum of 9 or an odd number with two
number cubes.

9 = (5,4)(4,5)(3,6)(6,3)
P(9) = 4/36
P(odd) = P(3) + P(5) + P(7) + P(9) + P(11)
Note that P(9) is included in P(odd).