Home/Notes/Arithmetic Word Problems
Board Exam Notes

Arithmetic Word Problems Notes

Questions

4–6 questions in major competitive exams

Difficulty

Medium

Importance

High yield for SSC and banking clerical cadres

Overview

Arithmetic Word Problems form the backbone of quantitative aptitude for Indian government exams, bridging the gap between basic calculation and logical reasoning. Mastering these allows candidates to translate real-world scenarios into mathematical expressions quickly, which is essential for scoring in the strict time constraints of exams like SSC CGL and IBPS.

Percentages and Profit & Loss

These topics revolve around base values and percentage changes. For exam success, move away from long-form algebraic equations and focus on fraction-to-percentage conversions to accelerate calculations.

  • Fraction to percentage conversion table (1/2 to 1/20)
  • Successive percentage change formula: (a+b + ab/100) percent
  • Profit percent = (Gain/Cost Price) * 100
  • Marked Price - Discount = Selling Price
  • Effect of successive discounts on net price

Time, Speed, and Distance

This subtopic tests your ability to handle relative speed and unit conversions. It is critical to convert all units into m/s or km/hr consistently before performing arithmetic operations.

  • Distance = Speed * Time
  • Average Speed = (2 * S1 * S2) / (S1 + S2) for equal distances
  • Relative Speed: S1+S2 (opposite), |S1-S2| (same direction)
  • Convert km/hr to m/s by multiplying by 5/18
  • Trains passing objects: length of train + length of platform

Time and Work

Efficiency-based problems require you to treat total work as a constant or the Least Common Multiple (LCM) of the given times. This method drastically reduces the complexity of variable-heavy equations.

  • Total Work = Efficiency * Time
  • Individual efficiency = Total Work / Time taken
  • If A takes x days and B takes y days, A+B finish in (xy)/(x+y) days
  • M1D1H1 / W1 = M2D2H2 / W2 (Chain Rule)
  • Work done by women/men/children based on ratios

Ratio, Proportion, and Ages

Ages and ratios are solved most effectively using multiplier variables. Always check if the ratio provided is for the present, past, or future to avoid phase-based calculation errors.

  • Cross-multiplication method for age ratio problems
  • Mean proportional of a and b is square root of (ab)
  • Componendo and Dividendo rule
  • Maintaining age gap consistency (age difference remains constant)
  • Direct and Inverse variation relationships

Formula Sheet

Distance = Speed * Time

Total Work = Efficiency * Time

Successive Change = x + y + xy/100

Average Speed = Total Distance / Total Time

Profit = Selling Price - Cost Price

Exam Tip

Instead of solving for 'x', use the ratio-multiplier method or the LCM method to bypass heavy arithmetic and save at least 30 seconds per question.

Common Mistakes

  • Failing to convert units (e.g., mixing km/hr with seconds) leading to incorrect distance values.
  • Applying simple interest logic to compound interest problems or vice-versa.
  • Misinterpreting 'more than' or 'less than' phrasing in ratio and percentage questions.

More Revision Notes

Ready to test yourself?

Play topic-wise Arithmetic Word Problems questions in Aspirant Arcade — gamified MCQ practice.

Download Free