If [tex]p \Rightarrow q[/tex] and [tex]q \Rightarrow r[/tex], which statement must be true?

A. [tex]p \Rightarrow r[/tex]

B. [tex]p \Rightarrow s[/tex]

C. [tex]s \Rightarrow p[/tex]

D. [tex]r \Rightarrow p[/tex]



Answer :

To solve this question, let's carefully analyze the given logical statements and their implications.

We are provided with two logical implications:
1. [tex]\( p \Rightarrow q \)[/tex]
2. [tex]\( q \Rightarrow r \)[/tex]

Our goal is to determine which statement must be true based on these implications.

### Step-by-Step Analysis:

Step 1: Understand the Meaning of Logical Implications

- [tex]\( p \Rightarrow q \)[/tex] means that if [tex]\( p \)[/tex] is true, then [tex]\( q \)[/tex] must also be true.
- [tex]\( q \Rightarrow r \)[/tex] means that if [tex]\( q \)[/tex] is true, then [tex]\( r \)[/tex] must also be true.

Step 2: Use Transitivity of Implications

We need to link these implications to find out a direct relationship between [tex]\( p \)[/tex] and [tex]\( r \)[/tex].

- Since [tex]\( p \Rightarrow q \)[/tex] and [tex]\( q \Rightarrow r \)[/tex], we can deduce that if [tex]\( p \)[/tex] is true, then [tex]\( q \)[/tex] must be true (by the first statement).
- Similarly, if [tex]\( q \)[/tex] is true, then [tex]\( r \)[/tex] must be true (by the second statement).

Combining these, we can conclude:
- If [tex]\( p \)[/tex] is true, then [tex]\( q \)[/tex] is true, and since [tex]\( q \)[/tex] is true, [tex]\( r \)[/tex] must also be true.

Thus, if [tex]\( p \)[/tex] is true, [tex]\( r \)[/tex] must be true. This gives us:
[tex]\[ p \Rightarrow r \][/tex]

### Step 3: Verify the Given Options

Now, let's check the given options to find the correct one:

- Option A: [tex]\( p \Rightarrow r \)[/tex]
- Option B: [tex]\( p \Rightarrow s \)[/tex]
- Option C: [tex]\( s \Rightarrow p \)[/tex]
- Option D: [tex]\( r \Rightarrow p \)[/tex]

From our deduction, we see that the true statement is:
[tex]\[ p \Rightarrow r \][/tex]

So, the correct answer is:

A. [tex]\( p \Rightarrow r \)[/tex]