NMAT Data Interpretation Syllabus

In a combination bar-and-line chart, what do the two axes typically represent?

The left (primary) axis usually scales the bars and the right (secondary) axis scales the line, so each series must be read against its correct axis.

What is Data Sufficiency (DS)?

A question type giving a question plus two statements; you must determine whether the statements provide enough information to answer, without necessarily computing the answer.

State the five standard Data Sufficiency answer options.

(A) Statement 1 alone sufficient, 2 not; (B) Statement 2 alone sufficient, 1 not; (C) Both together sufficient, neither alone; (D) Each alone sufficient; (E) Both together still insufficient.

In Data Sufficiency, what does 'sufficient' mean?

The information allows a single, definite answer to the question; if it yields multiple possible answers, it is insufficient.

What is the correct order to evaluate statements in Data Sufficiency?

Test Statement 1 alone, then Statement 2 alone (independently, not carrying over info), and only combine them if neither is sufficient alone.

Why should you NOT carry information from Statement 1 when testing Statement 2 in DS?

Each statement must be judged on its own; carrying over information would wrongly evaluate Statement 2 and corrupt the (A)/(B)/(D) determination.

What is the percentage change formula used throughout DI?

Percentage change = ((New value - Old value) / Old value) x 100. A positive result is growth; negative is decline.

What is the percentage formula for 'A is what percent of B'?

(A / B) x 100.

What is the fraction-to-percentage approximation for 1/7, 1/8, 1/9, and 1/11?

1/7 = ~14.28%, 1/8 = 12.5%, 1/9 = ~11.11%, 1/11 = ~9.09%.

What is the percentage equivalent of 1/3, 2/3, 1/6, and 5/6?

1/3 = ~33.33%, 2/3 = ~66.67%, 1/6 = ~16.67%, 5/6 = ~83.33%.

What is the digit-rounding technique to speed up DI calculations?

Round numbers to convenient values (nearest ten/hundred or simple fractions) to estimate quickly, then refine only if answer choices are close together.

When comparing two fractions a/b and c/d quickly, what cross-multiplication rule applies?

a/b > c/d if a x d > b x c (with positive denominators); compare the cross products instead of finding common denominators.

What is the percentage-comparison shortcut for choosing the larger of two ratios with similar values?

Compare relative changes: the ratio with the larger numerator increase and smaller denominator increase is greater; use approximation to avoid full division.

How do you compute a simple average (arithmetic mean) in DI?

Average = Sum of all values / Number of values.

What is the formula for a weighted average?

Weighted average = (Sum of (value x weight)) / (Sum of weights).

What is Compound Annual Growth Rate (CAGR) and its formula?

CAGR is the constant annual growth rate over a period: CAGR = ((Final value / Initial value)^(1/n)) - 1, where n is the number of years.

What is the difference between absolute growth and percentage growth?

Absolute growth is the raw difference (New - Old) in units; percentage growth expresses that difference relative to the old value as a percent.

Why can a smaller absolute increase show a larger percentage growth?

Because percentage growth depends on the base: a small increase on a small base can be a larger percent than a bigger increase on a large base.

What is the ratio comparison method for finding which year had the highest percentage growth?

Compute (increase / previous-year value) for each year and compare; the largest ratio is the highest percentage growth, not necessarily the largest absolute jump.

In growth analysis, how do you find a value after two successive percentage changes of x% then y%?

Net multiplier = (1 + x/100)(1 + y/100); final value = original x net multiplier. The net percentage = x + y + (xy/100).

What is the successive-percentage-change formula for two changes of +x% and -x%?

Net change = -x^2/100 (a net decrease), so equal up-then-down percent changes never return to the original value.

What is the standard approach to a data-based word problem in DI?

Extract the relevant figures from the data, translate the question into an arithmetic/algebraic relationship, compute, then sanity-check against the data.

How do you find the ratio between two quantities from a chart?

Read both values from the data and express as Value1 : Value2, then simplify by dividing both by their greatest common divisor.

How do you compute the percentage contribution of one category to a total?

Percentage contribution = (Category value / Total of all categories) x 100.

What is the formula to find the original value when a value after an r% increase is known?

Original = Final / (1 + r/100). For an r% decrease, Original = Final / (1 - r/100).

In DI, how do you handle questions asking for 'approximate' answers?

Round aggressively and estimate; pick the closest option since exact computation is unnecessary and wastes time when choices are spread apart.

What is the key to reading a chart with an axis that does not start at zero?

Recognize that visual bar heights exaggerate differences; always use actual axis values, not apparent proportions, when computing.

How do you compute the difference between two sectors of a pie chart in value terms?

Take the percentage (or angle) difference between the sectors and multiply by the total: Difference = ((P1 - P2)/100) x Total.

What does it mean when a Data Sufficiency question can be answered 'Yes' or 'No' depending on the statement?

If a statement forces a single definite Yes or a single definite No, it is sufficient; if it allows both Yes and No, it is insufficient.

What is the recommended scanning order before solving any DI set?

First read titles, axis labels, units, and the legend; then note the question's units to avoid scale and unit-mismatch errors.

How do you find the average rate of growth over n periods from a line graph?

Average growth rate = (Total change over the period / Initial value / n) x 100, or use CAGR for compounded growth across the n periods.