Correct Answer
✅ Option a — 8
All Options:
- A8
- B10
- C12
- DNone of these
Detailed Solution & Explanation
**1. Literal Evaluation of the Printed Question:**
Given the function:
We substitute into the expression:
Since $16\displaystyle is not among the options (a) 8, (b) 10, or (c) 12, the mathematically correct option for the printed text is **Option D** (None of these).<br><br>**2. Source of Discrepancy & Typographical Error:**<br>The function contains a typographical printing error where a prefix '3$' was added to $x^2x = 2\displaystyle :<br><span class="katex-display"><span class="katex"><span class="katex-mathml"><math xmlns="http://www.w3.org/1998/Math/MathML" display="block"><semantics><mrow><mi>f</mi><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo><mo>=</mo><mo stretchy="false">(</mo><mn>2</mn><msup><mo stretchy="false">)</mo><mn>2</mn></msup><mo>+</mo><mn>2</mn><mo stretchy="false">(</mo><mn>2</mn><mo stretchy="false">)</mo><mo>=</mo><mn>4</mn><mo>+</mo><mn>4</mn><mo>=</mo><mn>8</mn></mrow><annotation encoding="application/x-tex">f(2) = (2)^2 + 2(2) = 4 + 4 = 8</annotation></semantics></math></span><span class="katex-html" aria-hidden="true"><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord mathnormal" style="margin-right:0.10764em;">f</span><span class="mopen">(</span><span class="mord">2</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:1.1141em;vertical-align:-0.25em;"></span><span class="mopen">(</span><span class="mord">2</span><span class="mclose"><span class="mclose">)</span><span class="msupsub"><span class="vlist-t"><span class="vlist-r"><span class="vlist" style="height:0.8641em;"><span style="top:-3.113em;margin-right:0.05em;"><span class="pstrut" style="height:2.7em;"></span><span class="sizing reset-size6 size3 mtight"><span class="mord mtight">2</span></span></span></span></span></span></span></span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:1em;vertical-align:-0.25em;"></span><span class="mord">2</span><span class="mopen">(</span><span class="mord">2</span><span class="mclose">)</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.7278em;vertical-align:-0.0833em;"></span><span class="mord">4</span><span class="mspace" style="margin-right:0.2222em;"></span><span class="mbin">+</span><span class="mspace" style="margin-right:0.2222em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">4</span><span class="mspace" style="margin-right:0.2778em;"></span><span class="mrel">=</span><span class="mspace" style="margin-right:0.2778em;"></span></span><span class="base"><span class="strut" style="height:0.6444em;"></span><span class="mord">8</span></span></span></span></span><br>This matches **Option A** (8) perfectly, which explains why the answer key designated Option A as correct.<br><br>Hence, **Option A** is the correct answer (according to the textbook key and the intended function), but the literal mathematical result for the printed text is $16, which would correspond to **Option D**.
About This Chapter: Sets, Relations and Functions
Paper
Paper 3: Quantitative Aptitude
Weightage
3-5 Marks
Key Topics
Sets, Relations, Functions
This chapter covers Sets, Relations, Functions and is part of Paper 3: Quantitative Aptitude in the CA Foundation exam.
View Official ICAI SyllabusExam Strategy Tip
This topic carries 3-5 Marks weightage. Focus on understanding core concepts rather than memorizing.
Related Comparison Tables
More Questions from Sets, Relations and Functions
If , and then is:
If
Out of a group of $20$ teachers in a school, $10$ teach Mathematics,
If
The number of subsets of the set
If
Ready to Master Sets, Relations and Functions?
Practice all 222 questions with instant feedback, earn XP, track your streaks, and ace your CA Foundation exam.
Start Practicing — It's Free