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RRB NTPC Mathematics (Quantitative Aptitude) Flashcards
50 question-and-answer cards covering Mathematics (Quantitative Aptitude) as it is examined in RRB NTPC. 24 of them are printed below, taken from across the deck — no signup, no paywall on the preview.
24 sample cards from the Mathematics (Quantitative Aptitude) deck
Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.
How is profit or loss percentage calculated?
Profit% = (Profit / Cost Price) × 100; Loss% = (Loss / Cost Price) × 100. Both are calculated on the Cost Price (CP).
Define Cost Price (CP), Selling Price (SP), and Marked Price (MP).
CP: price at which an article is bought. SP: price at which it is sold. MP: the labelled/list price before discount.
What is the formula relating SP and CP using profit%?
SP = CP × (100 + Profit%) / 100. For a loss: SP = CP × (100 - Loss%) / 100.
How is discount calculated?
Discount is given on the Marked Price. Discount% = (Discount / Marked Price) × 100, and SP = MP - Discount.
If two articles are sold at the same SP, one at x% profit and the other at x% loss, what is the overall result?
There is always an overall loss of (x^2/100)%.
What is the formula for Simple Interest (SI)?
SI = (P × R × T) / 100, where P = principal, R = rate per annum, T = time in years.
What is the formula for the Amount in Simple Interest?
Amount = Principal + Simple Interest = P + (P × R × T)/100 = P(1 + RT/100).
What is the formula for Compound Interest amount (compounded annually)?
Amount = P × (1 + R/100)^T, and Compound Interest = Amount - P, where T is the number of years.
How is compound interest amount calculated when compounded half-yearly?
Amount = P × (1 + (R/2)/100)^(2T): the rate is halved and the time period is doubled.
For the same P, R, and T, how do SI and CI compare?
CI is always greater than SI (for T greater than 1 year) because CI earns interest on accumulated interest; they are equal for the first year.
What is the difference between CI and SI for 2 years?
Difference = P × (R/100)^2, where P is principal and R is rate per annum.
What is the formula for average?
Average = (Sum of all observations) / (Number of observations).
What is the average of the first n natural numbers?
Average = (n + 1) / 2.
If the average of n numbers is A, and a new number is added making the count n+1 with the average unchanged, what is the new number?
The new number must equal A (the average itself), since adding the average keeps the average the same.
What is the formula for the average speed for equal distances at speeds x and y?
Average speed = 2xy / (x + y), the harmonic mean of the two speeds.
What is alligation, and what does the rule of alligation find?
Alligation is a method to find the ratio in which two ingredients at different prices/concentrations must be mixed to get a mixture at a given mean price/concentration.
State the rule of alligation formula.
(Quantity of cheaper)/(Quantity of dearer) = (Price of dearer - Mean price)/(Mean price - Price of cheaper).
A container has milk and water. If x liters of milk is removed and replaced with water n times, what fraction of milk remains?
Remaining milk = Initial quantity × (1 - x/Total)^n.
In Time and Work, if A can do a job in n days, what is A's one-day work?
A's one day's work = 1/n of the total work.
If A does a job in x days and B in y days, how long do they take working together?
Together they take xy/(x + y) days, since combined one-day work = 1/x + 1/y.
What is the relationship between efficiency and time taken to complete work?
Efficiency is inversely proportional to time. If A is twice as efficient as B, A takes half the time B takes. Ratio of efficiencies = inverse ratio of times.
State the work equivalence formula (M1 D1 / W1 = M2 D2 / W2).
(M1 × D1 × H1)/W1 = (M2 × D2 × H2)/W2, where M = men, D = days, H = hours/day, W = work. Used in chain rule problems.
If A and B together finish a work in T days and A alone in a days, how long does B alone take?
B's time = (a × T) / (a - T) days, derived from 1/B = 1/T - 1/a.
What is the percentage equivalent of the fractions 1/4, 1/3, and 2/3?
1/4 = 25%, 1/3 = 33.33%, 2/3 = 66.67%.
What this deck covers
The Mathematics (Quantitative Aptitude) deck follows the RRB NTPC Mathematics (Quantitative Aptitude) syllabus — 5 chapters and 26 topics — so questions land on material that is genuinely examinable rather than trivia around it. That works out to roughly 10.0 cards per chapter.
Answers are written to be recallable, not just readable — averaging about 87 characters, which is long enough to carry the reasoning and short enough to say out loud.
A deck like this earns its keep on the second and third pass. Read the syllabus first so you know the shape of the subject, then use the cards to find the specific facts that have not stuck.
Mathematics (Quantitative Aptitude) flashcards FAQ
How many Mathematics (Quantitative Aptitude) flashcards are in this RRB NTPC deck?
50 cards. This page previews 24 of them, sampled evenly across the deck so you can judge the difficulty before installing anything.
Are these RRB NTPC flashcards free?
Yes. The preview here is free to read with no signup, and the full 50-card deck is free inside the Examius app.
What do the Mathematics (Quantitative Aptitude) cards cover?
They follow the RRB NTPC Mathematics (Quantitative Aptitude) syllabus — 5 chapters and 26 topics — so the questions track what is actually examinable.
How should I use these flashcards?
Read the syllabus first so you know the shape of the subject, then drill the deck. Examius schedules each card with spaced repetition, so cards you keep missing come back sooner and ones you know drift further apart.