.
(a) the computers can be ordered in different ways (permutations).
For 12 computers, there are 12! = 12*11*10* . . . *3*2*1 ways to order them.
If the computer with the missed component is the first one, then all the other 11 computers can be arranged in 11! ways.
So, the full space of events has 12! events, of them, only 11! events are favorable.
The probability that the defected computer will be checked first is the ratio = = . ANSWER
(b) If the first computer is OK, then with 11 remaining computers we have similar situation as with 12 computers
in part (a) above.
So, the answer in case (b) is P = due to the similar reasons. ANSWER
(c) The answers in parts (a) and (b) are different, because the space of events are different and the favorable sub-space
are different.
I completed the solution. // all your questions are answered.
-----------------
For introductory lessons on Elementary Probability theory see the lessons
- Simple and simplest probability problems
- Solving probability problems using complementary probability
- Elementary Probability problems related to combinations
- A True/False test
- A multiple choice answers test
- Conditional probability problems
- Typical probability problems from the archive
- Experimental probability problems
- Elementary operations on sets help solving Probability problems
in this site.
Also, you have this free of charge online textbook in ALGEBRA-II in this site
- ALGEBRA-II - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Solved problems on Probability".
Save the link to this textbook together with its description
Free of charge online textbook in ALGEBRA-II
https://www.algebra.com/algebra/homework/complex/ALGEBRA-II-YOUR-ONLINE-TEXTBOOK.lesson
into your archive and use when it is needed.
Consider these lessons as your textbook, handbook, a Solutions Manual, tutorials and (free of charge) home teacher.
Happy learning (!)