True Discount
View Questions of True Discount
True Discount
Quantitative Aptitude - True Discount
Understand present worth and discount concepts in bill payments before due dates.
1. Key Definitions
- Present Worth (PW): The amount which if invested now will become the amount due at maturity.
- True Discount (TD): Difference between amount due and present worth.
- Banker's Discount (BD): Simple Interest on face value for the time until maturity.
2. Formulas
- \( TD = \frac{A \times R \times T}{100 + R \times T} \)
- \( PW = \frac{A \times 100}{100 + R \times T} \)
- \( TD = SI - SI\text{ on }PW \)
3. Example
Amount = ₹1000, Rate = 10% p.a., Time = 1 year
- PW = \( \frac{1000 \times 100}{110} = ₹909.09 \)
- TD = 1000 - 909.09 = ₹90.91
4. Tips
- Always compute PW first to get TD.
- Use TD formula directly when amount and rate given.
5. Mistakes to Avoid
- Using simple interest formula instead of true discount when question explicitly says ‘true discount’.
Topics
- Number System
- H.C.F. & L.C.M.
- Decimal Fractions
- Simplification
- Square Roots & Cube Roots
- Average
- Problems on Numbers
- Problems on Ages
- Surds & Indices
- Percentage
- Operations on Numbers
- Profit & Loss
- Ratio & Proportion
- Partnership
- Chain Rule
- Time & Work
- Pipes & Cistern
- Time & Distance
- Problems on Trains
- Boats & Streams
- Alligation or Mixture
- Simple Interest
- Compound Interest
- Logarithms
- Area
- Volume & Surface Areas
- Mensuration
- Races & Games of Skill
- Calendar
- Clocks
- Stocks & Shares
- Permutations & Combinations
- Probability
- True Discount
- Banker’s Discount
- Heights & Distances
- Odd Man Out & Series
- Algebra
- Divisibility Rules & Remainder Theorem
- Factorials & Power Cycles
- Progressions (A.P., G.P., H.P.)
- Work & Wages
- Set Theory / Venn Diagrams
- Geometry (Lines, Angles, Triangles, Polygons)
- Coordinate Geometry
- Data Interpretation
- Trigonometry
- Statistics (Mean, Median, Mode)
- Arithmetic Operations
- Quadratic Equations
Other Subjects
- Prestressed Concrete
- Fluid Mechanics
- Geotechnical Engineering
- Ground Improvement Techniques
- Groundwater Engineering
- Highway Engineering
- Hydraulics and Hydraulic Machines
- Hydrology
- Irrigation Engineering
- Open Channel Flow
- Pavement Design
- Estimation, Costing and Valuation
- Railway Engineering
- Soil Mechanics
- Strength of Materials
- Structural Analysis
- Surveying
- Traffic Engineering
- Transportation Engineering
- Wastewater Treatment
- Water Supply and Sanitation
- Contracts and Specifications
- Reasoning
- Engineering Mathematics
- Air Pollution and Control
- Bridge Engineering
- Building Materials and Construction
- Concrete Technology
- Construction Equipment
- Construction Planning and Management
- Quantitative Aptitude
- Dam Engineering
- Design of RCC Structures
- Design of Steel Structures
- Drainage Engineering
- Earthquake Engineering
- Engineering Geology
- Engineering Graphics
- Engineering Mechanics
- Environmental Engineering
- General Awareness / General Knowledge (GK)