Probability?

Question

what is the probablitity ..
you roll a blue number cube and a green number cube. Find the probability


P(blue and green less than 7)

Answer 1

There are 36 possible outcomes (6 x 6).

Here are the good rolls that will be less than 7:
1, 1
1, 2
1, 3
1, 4
1, 5

2, 1
2, 2
2, 3
2, 4

3, 1
3, 2
3, 3

4, 1
4, 2

5, 1

In summary:
If blue roll is 1, green roll must be 1 through 5
If blue roll is 2, green roll must be 1 through 4
If blue roll is 3, green roll must be 1 through 3
If blue roll is 4, green roll must be 1 through 2
If blue roll is 5, green roll must be 1
If blue roll is 6, green roll can't be anything and be under 7...)

5 + 4 + 3 + 2 + 1 (+ 0) = 15

Good outcomes: 15
Total possible outcomes: 36

The probability (sum of blue and green is < 7):
=15/36
= 5/6

Answer 2

6 sided number cube with numbers 1-6????
If so
you could get
1+5 1+4 1+3 1+2 1+1
2+4 2+3 2+2 2+1
3+3 3+2 3+1
4+2 4+1
5+1
thats 15 out of 36 possibilities
15/36=about 42%