Discount · solved example
The marked price of an item is Rs 2000 and a discount of 25% is given. Find the price paid.
- 1700
- 1650
- 1350
- 1300
- 1500Correct
Solution
Discount is 25% of 2000 = 500, so the price paid is Rs 1500.
Railways | RRB Group D
Mathematics for RRB Group D
RRB Group D sets 25 Mathematics questions for 25 marks in the Computer Based Test, so it is worth planning your preparation around the topics below.
25 questions25 marks13 topics
How to approach Mathematics in RRB Group D
The quantitative core of the railway papers: arithmetic, mensuration, and time-speed-distance built on a secondary-school foundation. Fluency with fractions, percentages and ratios underlies almost every question, so that is where practice pays back fastest.
Weightage in the paper
How much Mathematics is worth in each RRB Group D stage, from the official pattern.
| Stage | Questions | Marks | Time | Share |
|---|---|---|---|---|
| Computer Based Test | 25 | 25 | — | 25% |
Mathematics syllabus for RRB Group D
Every topic in the official syllabus. The linked ones open a set of solved questions you can practise straight away.
- Number system, BODMAS, decimals and fractions
- LCM and HCF
- Ratio and proportion
- Percentage
- Mensuration
- Time and work
- Time, speed and distance
- Simple and compound interest
- Profit and loss
- Algebra at school level
- Geometry and trigonometry at school level
- Elementary statistics
- Square root, age calculations and calendar and clock
Sample Mathematics questions with solutions
Written to the RRB Group D pattern, with the answer key and the method behind it — a look at how the section is actually set before you drill the full topic sets.
Time, speed and distance · solved example
A train 180 metres long crosses a pole in 12 seconds. What is its speed in kilometres per hour?
- 45 km/h
- 48 km/h
- 54 km/hCorrect
- 60 km/h
Solution
Crossing a pole means the train covers exactly its own length, so the speed is 180/12 = 15 metres per second. To convert metres per second into kilometres per hour, multiply by 18/5: 15 x 18/5 = 54 km/h. Remember that a train crossing a platform or bridge covers its own length plus that of the platform.
Time and work · solved example
A can do a work in 10 days and B in 15 days. Working together, in how many days will they finish it?
- 7
- 6Correct
- 8
- 5
Solution
Together they do 1/10 + 1/15 = 1/6 of the work a day, so it takes 6 days.
Mensuration · solved example
Find the volume of a cube whose edge is 6 cm.
- 206
- 196
- 216Correct
- 225
Solution
Volume of a cube = edge³ = 6³ = 216 cm³.
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Mathematics study material
Sit Mathematics under a real clock
Mathematics shows up in every RRB Group D mock test, in the same interface, with sectional locking and negative marking.
Frequently asked questions
How many Mathematics questions are asked in RRB Group D?
RRB Group D Latest notified cycle sets 25 Mathematics questions for 25 marks in the Computer Based Test.
Is there negative marking for Mathematics in RRB Group D?
Yes. RRB Group D deducts one third of a mark for each wrong answer, Mathematics included, so unsure guesses cost you. One third of a mark is deducted for each wrong answer. Questions left blank carry no penalty.
Which Mathematics topics matter most for RRB Group D?
The RRB Group D syllabus lists Number system, BODMAS, decimals and fractions, LCM and HCF, Ratio and proportion, Percentage, Mensuration, Time and work and more. Weight your revision towards the ones you are weakest on and confirm the emphasis against the paper analysis for recent cycles.
How can I practise Mathematics for RRB Group D free?
Every Mathematics question on this site is free and written to the exam pattern. Use the topic drills for instant-feedback practice, the daily quiz to keep the section warm, and the RRB Group D mock tests to sit it under a real clock with negative marking.