Question 1167755
.


For part (a), I just answered under this link


<A HREF=https://www.algebra.com/algebra/homework/Probability-and-statistics/Probability-and-statistics.faq.question.1167754.html>https://www.algebra.com/algebra/homework/Probability-and-statistics/Probability-and-statistics.faq.question.1167754.html<A>


https://www.algebra.com/algebra/homework/Probability-and-statistics/Probability-and-statistics.faq.question.1167754.html



<pre>
(b, i)  In this case, you consider COMBINATIONS of 10 digits taken 4 at a time.


        There are  {{{C[10]^4}}} = {{{(10*9*8*7)/(1*2*3*4)}}} = 210  such combinations, in all.


        Of them, only one is winning.


        Therefore, the probability to win is  {{{1/210}}}  in this case.
</pre>

Solved.


-----------


Do not pack many problems/questions in one post.

It is against the rules of this forum, and it really irritates.



&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;And it is against your own interests.



Also, do not repeat that parts, what were just solved for you by tutors earlier.