you roll 2 dice. What is the probability that the total of the two dice is even or that the total is less than 5?

Question

amistre64 · Answer

less than 5

   1 2 3 4 5 6
1 x x x 
2 x x
3 x
4
5
6

include all the even sums:

   1 2 3 4 5 6
1 x x x     x
2 x x    x     x
3 x   x     x
4   x    x      x
5 x   x     x 
6   x    x      x

amistre64 · Answer

20/36 = 5/9 perhaps?

amistre64 · Answer

if you do the formula, you have to subtract the ones that you count double. those P(A and B) stuff

amistre64 · Answer

P(A or B) = P(A) + P(B) - P(A and B)

P(x<5; or x=even) = 6/36 + 18/36 - 4/36
                            = 2/36 + 18/36
                            = 20/36
                            = 5/9

anonymous · Answer

Thanks!