Placement Aptitude (Quant, Logical, Verbal) Module 19 – Reading, ordering and writing
Reading comprehension: inference and tone
Draw inferences a passage supports, name its tone and purpose, and answer strengthen and weaken questions set on passages, from the text alone.
What you will learn
- Infer only what a passage makes certain, telling must-be-true options from could-be-true ones
- State the purpose of a passage, or of one part of it, with a verb such as argue, refute or warn
- Name an author's tone from the author's own judging words, not from quotations
- Choose the option that strengthens or weakens a passage's argument by the gap it closes or opens
Before you start
What you’ll learn · Before you start
What you will learn
- Infer only what a passage makes certain, telling must-be-true options from could-be-true ones
- State the purpose of a passage, or of one part of it, with a verb such as argue, refute or warn
- Name an author's tone from the author's own judging words, not from quotations
- Choose the option that strengthens or weakens a passage's argument by the gap it closes or opens
Before you start
On this page
“Every second-floor room has a ceiling fan.” Does room 212, on the second floor, have a fan? It must, and that is an inference: A conclusion that a passage makes certain without stating it: if every sentence of the passage is true, the inference is true too. An option that is only probable is not an inference.: something the passage makes certain without saying it in so many words. The test is strict, because an inference must be true whenever every sentence of the passage is true, so an option that could be true, or is probably true, is not enough. Tone questions ask how the author feels about the subject, read from the judging words the author chooses, and purpose questions ask why the author wrote the passage, or one part of it. All three are answered from the passage alone.
CAT 2026 gives its Verbal Ability and Reading Comprehension section exactly 40 minutes, so on that test, choosing which passages to attempt matters as much as answering them.
An inference must be true in every case the passage allows
Take a short passage: “Every second-floor room has a ceiling fan. Some second-floor rooms also have a cooler. No room with a cooler faces the road.” If room 212 is on the second floor, “room 212 has a fan” must be true, “room 212 has a cooler” only could be, and “room 212 has no fan” cannot be. “Every room with a fan is on the second floor” reads the first sentence backwards, a common trap. Options with always, never, all or none need words just as strong in the passage. The figure is the test as three questions:
Must be true, could be true, cannot be true
Text description of the diagram
The diagram is a column of four boxes joined by arrows, from top to bottom:
- Take every sentence of the passage as true, and nothing more.
- Is the option true in every case the passage allows? If yes, it must be true: it is an inference.
- If not, is it true in some case? If yes, it could be true, but it is not an inference.
- If not, it cannot be true: the passage rules it out.
Inference questions want the first verdict. Options that only could be true are the commonest wrong answers.
The program lists every case the hostel passage allows and checks each option in all of them:
# The three-way test of an inference, done by brute force. The "passage" is four statements about three hostel rooms;
# the program lists every combination of facts the rooms could have (512 of them), keeps the ones in which all four
# statements are true, and checks each option in every one it kept. An option true in all of them must be true (an
# inference); true in some, it could be true; true in none, it cannot be true.
from itertools import product
ROOMS = ["212", "214", "101"] # 212 and 214 are on the second floor, 101 on the first
SECOND_FLOOR = {"212", "214"}
FACTS = ["fan", "cooler", "road"] # has a ceiling fan, has a cooler, faces the road
def passage_true(w):
return (
all(w[r, "fan"] for r in SECOND_FLOOR) # Every second-floor room has a ceiling fan.
and any(w[r, "cooler"] for r in SECOND_FLOOR) # Some second-floor rooms also have a cooler.
and all(not (w[r, "road"] and w[r, "cooler"]) for r in ROOMS) # No room with a cooler faces the road.
) # (Room 212 is on the second floor: ROOMS.)
OPTIONS = [
("Room 212 has a ceiling fan.", lambda w: w["212", "fan"]),
("Room 212 has a cooler.", lambda w: w["212", "cooler"]),
("Room 212 has no ceiling fan.", lambda w: not w["212", "fan"]),
("If room 212 faces the road, it has no cooler.", lambda w: not w["212", "road"] or not w["212", "cooler"]),
("Every room with a ceiling fan is on the second floor.", lambda w: not w["101", "fan"]),
("Some second-floor room does not face the road.", lambda w: any(not w[r, "road"] for r in SECOND_FLOOR)),
]
keys = [(r, f) for r in ROOMS for f in FACTS]
worlds = [dict(zip(keys, values)) for values in product([False, True], repeat=len(keys))]
kept = [w for w in worlds if passage_true(w)]
print(f"{len(worlds)} combinations of facts; the passage is true in {len(kept)} of them.")
print()
for text, holds in OPTIONS:
n = sum(holds(w) for w in kept)
verdict = "must be true" if n == len(kept) else "cannot be true" if n == 0 else "could be true"
print(f"{verdict:15} {n:3} of {len(kept)} {text}")Output
512 combinations of facts; the passage is true in 30 of them. must be true 30 of 30 Room 212 has a ceiling fan. could be true 18 of 30 Room 212 has a cooler. cannot be true 0 of 30 Room 212 has no ceiling fan. must be true 30 of 30 If room 212 faces the road, it has no cooler. could be true 15 of 30 Every room with a ceiling fan is on the second floor. must be true 30 of 30 Some second-floor room does not face the road.
Recorded with Python 3.14.8 on macOS 26 arm64. To run it yourself: mise exec python@3.14.8 -- python3 three_way.py
Runs on this device, in your browser. The first run downloads Python (about 13.5 MB), which is kept for the next runs.
Your run, in this browser
The last option needs two sentences at once: some second-floor room has a cooler, and no room with a cooler faces the road, so some second-floor room does not face it. Inferences that join two sentences are the ones careless readers miss.
Key idea
An option is an inference only if it holds in every case the passage allows; could be true is not enough.
Checkpoint
Check: Must be true, could be true, cannot be true
A purpose question is answered with a verb
The next three sections use one passage:
Open-book examinations are often dismissed as a holiday from study, as if a student allowed to carry a textbook into the hall could simply copy the answers. Anyone who has sat one knows better. A question that can be answered by finding the right page is a poor question in any examination, so setters of open-book papers ask students to apply an idea to a case the book never mentions. The book then helps only the student who already knows where everything is and why it matters; the rest spend the paper turning pages. Critics are right that such papers are harder to set and to mark. That is a cost to examiners, not a reason to call the paper easy.
It shows that open-book papers are wrongly called easy, and does not explain how they are set. Five verbs name most purposes:
| Verb | The author |
|---|---|
| explain | shows how or why something works, taking no side |
| argue | takes a side and gives reasons |
| refute | states a view to show it is wrong |
| compare | sets two things side by side |
| warn | points to a risk |
The passage takes a side with reasons, so it argues; since it states the critics’ view to show it is wrong, refute is more exact. The purpose of one part, such as an example, is usually to support, illustrate or concede.
Checkpoint
Check: A purpose named with a verb
Tone comes from the author’s own words, never from a quotation
The author’s tone towards the critics is measured disagreement: “Critics are right” grants a point, and “not a reason to call the paper easy” rejects their conclusion. Tone words form a ladder:
| Tone | It means |
|---|---|
| Scathing | Criticising very severely, without respect |
| Sceptical | Doubting that a claim is true |
| Ambivalent | Both positive and negative feelings |
| Objective | Facts, without the writer’s feelings |
| Laudatory | Expressing praise |
Step through five sentences placed on the ladder by their judging words:
The drawing shows the whole scene; its 5 steps are listed below.
Every step as text
- Careless and wrong. 'The report is careless and its numbers are wrong.' Two severe judgements and no respect for the report: scathing, the most negative rung.
- A closer look. 'The app's promise to double anyone's reading speed has not been tested outside the company.' The writer doubts the claim without calling it false: sceptical.
- A gift and a cost. 'The new road is a gift to walkers and a cost to the shops.' One positive and one negative judgement of the same thing: ambivalent.
- Two chapters. 'The syllabus adds two chapters and removes one.' Facts only, with no judging word at all: objective, whatever the reader thinks of the change.
- In a single summer. 'The volunteers rebuilt the library in a single summer.' In a single summer praises the speed of the work: laudatory, the most positive rung.
irony: Saying the opposite of what you mean, so that the words and the situation clash, as in 'Great, another Sunday spent revising.' writing says the opposite of what it means. Judge the tone of the whole passage, never the tone of one quotation in it: a passage may quote an angry critic and answer calmly.
Checkpoint
Check: Tone from the author's own words
Strengthen and weaken options act on the gap between evidence and conclusion
Find the conclusion and the evidence it rests on. A strengthener closes the gap between them, and a weakener opens it, often with another explanation; these are the only options allowed to bring in new facts. So test each option by what it does to the gap: a fact on the passage’s topic can still leave it untouched. Step through the open-book argument and two options for its strengthen question:
The drawing shows the whole scene; its 5 steps are listed below.
Every step as text
- The conclusion. The passage concludes that open-book papers are wrongly called easy.
- The evidence. Its evidence is that setters ask students to apply ideas to cases the book never mentions, so the book helps only students who already know it well.
- The gap. The gap is whether the book really gives an unprepared student nothing. If it helped them after all, the papers might still be easy for them.
- An option that closes it. 'In a trial, students who had not studied scored no better with the book than without it.' This closes the gap from the author's side, so it strengthens.
- An option that misses it. 'Open-book papers take longer to mark.' This supports the critics' point about examiners and leaves the gap where it was: no effect on the conclusion.
“In a trial, students who had not studied scored no better with the book than without it” closes the gap; “open-book papers take longer to mark” supports the critics’ point, not the conclusion.
Checkpoint
Check: Strengthen and weaken as a gap check
Practise: inference, purpose, tone and the gap
The exercise gives the three-way verdict for any option. Below it, untimed practice starts with the question type you are least sure of.
Exercise · Easy · Python
Must be true, could be true or cannot be true
An inference must be true in every case the passage allows. worlds is a list of those cases, each a dictionary of facts such as {"fan": True, "cooler": False}, and statement is a function that takes one case and returns True or False. Write verdict(worlds, statement), which returns:
"must be true"when the statement holds in every case: it is an inference;"cannot be true"when it holds in none: the passage rules it out;"could be true"otherwise: possible, but not an inference.
worlds always has at least one case. The starter code calls everything possible, which is the could-be-true trap that the sample tests catch.
Starter code · verdict.py
def verdict(worlds, statement):
""""must be true", "could be true" or "cannot be true": how a statement fares in the cases a passage allows."""
# Replace this line with your code: it calls every statement possible.
return "could be true"The sample tests · test_verdict.py
from verdict import verdict
# Two cases a passage allows: "Every room on this floor has a fan; some rooms also have a cooler."
ROOM = [{"fan": True, "cooler": True}, {"fan": True, "cooler": False}]
def test_must_be_true():
"""The fan is there in every case: an inference"""
assert verdict(ROOM, lambda w: w["fan"]) == "must be true"
def test_could_be_true():
"""A cooler in one case only: possible, not an inference"""
assert verdict(ROOM, lambda w: w["cooler"]) == "could be true"
def test_cannot_be_true():
"""No fan in no case: the passage rules it out"""
assert verdict(ROOM, lambda w: not w["fan"]) == "cannot be true"
def test_one_case():
"""With one case left, what holds in it must be true"""
assert verdict([{"fan": True, "cooler": False}], lambda w: not w["cooler"]) == "must be true"
def test_combined_statement():
"""A fan or a cooler: true in both cases"""
assert verdict(ROOM, lambda w: w["fan"] or w["cooler"]) == "must be true"A hint
Count the cases in which the statement holds: sum(1 for w in worlds if statement(w)). Compare that count with len(worlds) for "must be true" and with 0 for "cannot be true"; anything in between could be true.
Results of the sample tests
| Test | Result | Details |
|---|
What your code printed
The sample tests run on this device, in your browser (Pyodide): nothing is sent to mysmartcopilot.com. The first run downloads Python (about 13.5 MB), which is kept for the next runs. A check in your browser is feedback for you, not proof that the code is right for every input.
Practice that adapts to you
Practise this lesson
12 questions about 6 ideas of this lesson. Each answer is explained at once, and what you get right is kept in this browser.
Twelve inference, tone and purpose items, worked option by option Pro: opens with a Pro, Premium or Ultimate pass
Inference and tone options fail in a handful of ways, and every wrong option below is labelled with its way. Six questions on a new passage come first, then six single sentences whose tone is the whole question.
In this part:
- A passage with mixed feelings
- Six questions on it, every wrong option labelled
- Six sentences, six tones, worked
- The traps behind the wrong options
about 5 minutes
Opening this part with your pass…
This part opens with any MySmartCoPilot pass.
- Pro pass · 1 week₹79$2.99
- 30 days₹179$5.99
- 1 year₹1,699$45
One payment; a pass never renews. The price shown is the total you pay: no fees or charges are added at checkout.
Passes can’t be bought right now, so this part can’t be opened at the moment. The free part above stands on its own. If you have a pass, enter your licence key.
It also opens every other in-depth part in Learn and every Pro tool. Sales are final, except where the law gives you a right to withdraw, for example in the EU and the UK (refund policy).
Strengthen and weaken on a passage, measured by counting cases Pro: opens with a Pro, Premium or Ultimate pass
A strengthen or weaken option works on the gap between the evidence and the conclusion, and how far it moves an argument can be counted. This part counts it on one passage and then works three more items.
In this part:
- Find the gap before reading the options
- Four options measured by counting cases
- Three more items, worked
- Strengthen and weaken compared
1 runnable example (Python) · about 4 minutes
Opening this part with your pass…Pro part. It opens with the same pass as the part above.
A ten-minute timed set, with answers and a rubric Pro: opens with a Pro, Premium or Ultimate pass
One passage and eight questions, for ten minutes on the clock. Each worked answer quotes the words that settle it, and the rubric reads your score and your time as a plan for the next week of practice.
In this part:
- The passage
- Eight questions for ten minutes
- Worked answers, with the words behind each
- A rubric: what your score and time say
about 4 minutes
Opening this part with your pass…Pro part. It opens with the same pass as the part above.
Interview questions
-
Fresher · Warm-up
In a reading passage, what is the difference between an inference and an assumption?
An inference is a conclusion the passage makes certain: if every sentence of the passage is true, the inference must be true too, although the passage never states it. An assumption runs the other way: it is an unstated premise the author needs for the argument to work, something the passage takes for granted rather than something that follows from it. "The library now stays open late, so students study more" assumes that students use the late hours, and it lets you infer nothing about their marks. A quick test: an inference follows from the passage; an assumption, if it were false, would make the argument fall apart. Strengthen questions often confirm an assumption, and weaken questions often break one.
-
Fresher to mid
A candidate keeps choosing inference options that are probable rather than certain. Explain the error, and give a check that takes seconds and works on every inference question in a test.
-
Fresher to mid
A passage quotes an angry critic at length, then answers the critic calmly and ends with a proposal. A candidate marks the tone "angry". Explain the error, and how you would settle the tone of a passage in under a minute.
-
Fresher to mid
Candidates are often told that options with "always" or "never" are wrong. When is such an option the right answer? Write a passage sentence that would make one correct, and say how you would check it.
Key takeaways
- An inference must be true whenever the passage is true; an option that could be true is not enough.
- Name a purpose with a verb: explain, argue, refute, compare or warn.
- Judge tone from the author’s own judging words, never from a quotation.
- Strengthen and weaken options act on the gap between the evidence and the conclusion.
Terms in this lesson
- inference
- A conclusion that a passage makes certain without stating it: if every sentence of the passage is true, the inference is true too. An option that is only probable is not an inference.
- irony
- Saying the opposite of what you mean, so that the words and the situation clash, as in 'Great, another Sunday spent revising.'
References
- Press release for the Common Admission Test 2026 (CAT 2026): duration and sections (Indian Institute of Management Indore (CAT 2026))
- GATE 2027 General Aptitude syllabus: Verbal Aptitude (reading and comprehension) (Indian Institute of Technology Madras (GATE 2027))
- Informal Logic (arguments, premises, conclusions and unstated assumptions) (Stanford Encyclopedia of Philosophy)
- inference (noun), Oxford Learner's Dictionaries (Oxford University Press)
- sceptical (adjective), Oxford Learner's Dictionaries (Oxford University Press)
- ambivalent (adjective), Oxford Learner's Dictionaries (Oxford University Press)
- laudatory (adjective), Oxford Learner's Dictionaries (Oxford University Press)
- scathing (adjective), Oxford Learner's Dictionaries (Oxford University Press)
- ironic (adjective), Oxford Learner's Dictionaries (Oxford University Press)
- wry, nostalgic, apprehensive (adjectives), Oxford Learner's Dictionaries (Oxford University Press)
- refute (verb), Oxford Learner's Dictionaries (Oxford University Press)
- itertools: product (Python Software Foundation)
Related tools
Report a problem with this lesson
Kept only in this browser. Your Learn progress