NBT AQL cheat sheet

Conclusion = the claim the author wants accepted; premises = the reasons offered for it. Ask 'what does the author want me to accept, and on what grounds?'

Indicator words: therefore, thus, hence, so, consequently, it follows that → conclusion. Because, since, given that, as → premise.

An inference must be forced by the text; if an alternative reading fits the passage equally well, the inference is not supported.

Main idea = the single claim to which every paragraph contributes. Examples, statistics and anecdotes are support, not the main idea.

Tone is carried by word choice and modifiers, not by topic: 'the so-called reform' signals scepticism, 'the landmark reform' signals approval.

Hedged claims (may, tends to, in most cases, suggests) are weaker than absolute claims (always, never, proves). An answer option that overstates the text is wrong.

Fact = verifiable by evidence; opinion = evaluation, judgement or prediction. 'Unemployment rose 2%' is a fact; 'the policy failed' is an opinion.

Cohesive ties (pronouns, synonyms, however/therefore) mark logical relations: always resolve what 'this', 'such measures' or 'the former' refers to before answering.

Register: academic prose avoids slang and contractions and favours formal, impersonal vocabulary. The tone of a correct option must match the passage's register.

Part = whole × (percentage ÷ 100). Example: 15% of 240 = 0.15 × 240 = 36.

Percentage change = ((new − old) ÷ old) × 100. A rise from 40 to 50 is +25%; a fall from 50 to 40 is −20%.

Percentage points vs percent: a rate rising from 20% to 25% rises 5 percentage points, which is a 25% relative increase.

Direct proportion: doubling one quantity doubles the other (y = kx). Inverse proportion: doubling one halves the other (xy = k).

Unit rate: divide to get 'per one' - 300 km in 4 hours = 75 km/h. Multiply by the unit rate to scale to other amounts.

Mean = sum ÷ count; median = middle of ordered data; mode = most frequent value. Outliers shift the mean but barely move the median.

Simple interest: I = P × r × t. Compound interest: A = P(1 + r)^n, where r is the decimal rate per period and n the number of periods.

Convert units by multiplying by fractions equal to 1 so unwanted units cancel, e.g. × (1000 m ÷ 1 km).

Scale: map length ÷ actual length in the same units. A 1:50 000 map means 1 cm on the map represents 0.5 km on the ground.