#1**+10 **

1+12 1+6+6 1 way

2+11 2+5+6 2=6+5 2 ways

3+10 10=6+4 or 4+6, or 5+5 3 ways

4+9 9=6+3, 3+6, 5+4, 4+5 4 ways

5+8 8=6+2, 2+6, 5+3, 3+5, 4+4 5 ways

6+7 7=6+1, 1+6, 5+2, 2+5, 4+3, 3+4 6 ways

6+5+4+3+2+1=21

Total combinations $${{\mathtt{6}}}^{{\mathtt{3}}} = {\mathtt{216}}$$

P(sum of 13) = $${\frac{{\mathtt{21}}}{{\mathtt{216}}}} = {\frac{{\mathtt{7}}}{{\mathtt{72}}}} = {\mathtt{0.097\: \!222\: \!222\: \!222\: \!222\: \!2}}$$

Melody
Nov 21, 2014

#2**+10 **

Best Answer

I believe the probability of 13 is:

6 6 1 3 ways to do this

6 5 2 6 ways to do this

6 4 3 6 ways to do this

5 5 3 3 ways to do this

5 4 4 3 ways to do this =

21 total ways to roll a 13

So....the probability is

21 / 216 = 0.0972222222222222 = about 10%

CPhill
Nov 21, 2014