91Ó°ÊÓ

There are 5 copies of a certain text on reserve.

The first printing is two copies (1 and 2) and the second printing are other three copies (3, 4, and 5).

A possible outcome is 5 and another is 213.

a.

Let S represents the sample space.

For the provided scenario, the possible number of outcomes is,

\(S = \left\{ {\left( 3 \right),\left( 4 \right),\left( 5 \right),\left( {13} \right),\left( {14} \right),\left( {15} \right),\left( {23} \right),\left( {24} \right),\left( {25} \right),\left( {123} \right),\left( {124} \right),\left( {125} \right),\left( {213} \right),\left( {214} \right),\left( {215} \right)} \right\}\)

Here, the outcome 123 represents that the 1^st copy of 1^st printing, 2^nd copy of first printing, and 3^rd copy of second printing are examined and then the student stops.

b.

A represents the event that exactly one book must be examined.

The possible number of outcomes in A are,

\(A = \left\{ {3,4,5} \right\}\)

c.

B represents the event that book 5 is the one selected.

Event B will include all the events where book 5 is selected.

The possible outcomes are,

\(B = \left\{ {5,15,25,125,215} \right\}\)

d.

C represents the event that book 1 is not examined.

The possible outcomes included in the C are,

\(C = \left\{ {3,4,5,23,25} \right\}\)