Question 1160749
.


            There are two totally different problems in this post.


            Therefore,  I will answer  (b),  (c)  and  (d)  ONLY    (since these three parts logically comprise one problem)



<pre>
The probability to get the sum of 7 at each single roll a pair of dice is  {{{1/6}}}

     ( since there are 36 outcomes, in total, and only six are successful, 

     (1,6), (2,5), (3,4), (4,3), (5,2), and (6,1) ).


So the answers (and the solutions) are



(b)  P = {{{C[5]^3*(1/6)^3*(5/6)^2}}} = 0.03215.


(c)  P = 1 - {{{(5/6)^5}}} = 0.598122.


(d)  P = {{{(5/6)^5}}} + {{{C[5]^1*(1/6)*(5/6)^4}}} = 0.803755. 
</pre>