Question 1139895
.
<pre>
(a)  The total number of all possible combinations of numbers in this case is  {{{14^4}}} = 38416.

     It is because there are 14 possible independent opportunities in each of 4 positions.



(b)  The probability that every (any) fixed concrete combination will open the lock is therefore  {{{1/14^4}}} = {{{1/38416}}}.

     The probability that the combination {1-2-3-4} is the happy key is therefore also  {{{1/14^4}}} = {{{1/38416}}}.



(c)  If you try 25 different combinations of 4 numbers, the probability to open the lock is  {{{25/14^4}}} = {{{25/38416}}}.
</pre>

I answered ALL YOUR QUESTIONS.


Do not forget to post your "THANKS" to me immediately after reading my post.



/\/\/\/\/\/\/\/\/


By the way, this problem came to the forum some days ago, and I answered and solved it under this link


<A HREF=https://www.algebra.com/algebra/homework/word/misc/Miscellaneous_Word_Problems.faq.question.1139207.html>https://www.algebra.com/algebra/homework/word/misc/Miscellaneous_Word_Problems.faq.question.1139207.html</A>


https://www.algebra.com/algebra/homework/word/misc/Miscellaneous_Word_Problems.faq.question.1139207.html



&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;What is or what was the need to post it again ?