Which rule describes the relationship between the input and output pairs in the following table?

\begin{tabular}{|c|c|}
\hline
Input & Output \\
\hline
3 & 9 \\
\hline
5 & 15 \\
\hline
7 & 21 \\
\hline
\end{tabular}

Choose one answer:
A. Add 6 to the input to get the output.
B. Multiply the input by 3 to get the output.
C. Multiply the input by 2, then add 5 to the result to get the output.



Answer :

To solve the problem, let's consider each rule provided and see how it transforms the given inputs to the outputs.

The inputs and outputs given are as follows:
[tex]\[ \begin{array}{|c|c|} \hline \text{Input} & \text{Output} \\ \hline 3 & 9 \\ \hline 5 & 15 \\ \hline 7 & 21 \\ \hline \end{array} \][/tex]

Option A: Add 6 to the input to get the output

For each input:
- Input 3: [tex]\( 3 + 6 = 9 \)[/tex]
- Input 5: [tex]\( 5 + 6 = 11 \)[/tex]
- Input 7: [tex]\( 7 + 6 = 13 \)[/tex]

The outputs from this rule are [tex]\( \{9, 11, 13\} \)[/tex].

Option B: Multiply the input by 3 to get the output

For each input:
- Input 3: [tex]\( 3 \times 3 = 9 \)[/tex]
- Input 5: [tex]\( 5 \times 3 = 15 \)[/tex]
- Input 7: [tex]\( 7 \times 3 = 21 \)[/tex]

The outputs from this rule are [tex]\( \{9, 15, 21\} \)[/tex].

Option C: Multiply the input by 2. Then add 5 to the result to get the output

For each input:
- Input 3: [tex]\( 3 \times 2 + 5 = 6 + 5 = 11 \)[/tex]
- Input 5: [tex]\( 5 \times 2 + 5 = 10 + 5 = 15 \)[/tex]
- Input 7: [tex]\( 7 \times 2 + 5 = 14 + 5 = 19 \)[/tex]

The outputs from this rule are [tex]\( \{11, 15, 19\} \)[/tex].

Now, we need to compare the computed results with the given outputs [tex]\( \{9, 15, 21\} \)[/tex]:
- The outputs from Option A ([tex]\( \{9, 11, 13\} \)[/tex]) do not match the given outputs.
- The outputs from Option B ([tex]\( \{9, 15, 21\} \)[/tex]) match the given outputs perfectly.
- The outputs from Option C ([tex]\( \{11, 15, 19\} \)[/tex]) do not match the given outputs.

Therefore, the correct rule that describes the relationship between the input and output pairs is:

(B) Multiply the input by 3 to get the output.