Great Lakes - PGDM & PGPM Admissions 2027
Globally Recognized by AACSB (US) & AMBA (UK) | 18 LPA Avg. CTC for PGPM 2026
Search Colleges, Exams, Schools & more
Login
Simple Interest and Compound Interest questions in CAT often test more than direct formula application. Questions can combine rates, time periods, successive changes, half-yearly compounding and comparisons between SI and CI, making shortcut-based calculation especially useful. CAT 2026 is scheduled for November 29, 2026. This article covers the key SI and CI formulas, calculation tricks, important question types and CAT-level practice questions to strengthen Quantitative Aptitude preparation.
This Story also Contains
- CAT Simple Interest Formulas
- CAT Compound Interest Formulas
- CAT 2026 SI and CI Important Shortcuts
- CAT SI and CI Percentage Shortcuts
- CAT 2026 Simple Interest and Compound Interest Practice Questions
- CAT 2026 SI and CI Important Question Types
- Common Mistakes in CAT SI and CI Questions
- CAT 2026 SI and CI Quick Revision Formula Sheet
- CAT 2026 SI and CI Preparation Strategy
- CAT 2026 Mock Test
- How to Identify the Right SI or CI Formula in CAT
CAT 2026 Simple Interest and Compound Interest: Key Concepts
Understanding the difference between Simple Interest and Compound Interest is the first step toward solving interest-based questions quickly.
Concept | Simple Interest | Compound Interest |
Interest calculated on | Original principal | Principal plus accumulated interest |
Formula for interest | SI=P×R×T100 | CI=A−P |
Amount | A=P+SI | A=P(1+R100)T |
Interest growth | Linear | Compound growth |
Here, P represents the principal, R is the annual interest rate, T is the time in years and A is the final amount.
CAT Simple Interest Formulas
The key SI formulas for CAT cover interest, amount, principal, rate and time.
Simple Interest: SI=P×R×T100
Amount: A=P+SI=P(1+RT100)
Principal: P=100×SIR×T
Rate: R=100×SIP×T
Time: T=100×SIP×R
CAT Compound Interest Formulas
For CI, the compounding period determines the number of growth cycles.
Compound Amount: A=P(1+R100)T
Compound Interest: CI=A−P=P[(1+R100)T−1]
Depreciation: A=P(1−R100)T
CAT 2026 SI and CI Important Shortcuts
Several standard shortcuts can reduce calculation time in CAT.
Difference Between CI and SI for 2 Years
For a principal P and rate R:
CI−SI=P(R100)2 or
CI−SI=PR210000
For example, if ₹P=₹20,000 and R=10:
₹CI−SI=20000×10210000=₹200
Difference Between CI and SI for 3 Years
CI−SI=P[3(R100)2+(R100)3]
This formula is useful when a question directly asks for the difference between compound and simple interest over three years.
Half-Yearly Compounding
For half-yearly compounding, halve the rate and double the number of periods:
A=P(1+R200)2T
Quarterly Compounding
For quarterly compounding, divide the rate by 4 and multiply the periods by 4:
A=P(1+R400)4T
Different Interest Rates
If different rates apply during different periods:
A=P(1+R1100)T1(1+R2100)T2
CAT SI and CI Percentage Shortcuts
Percentage-based shortcuts are particularly useful in CAT questions involving repeated increases or decreases.
Successive Percentage Increase
If a value increases by a and then by b, the total percentage increase is:
a+b+ab100
Increase Followed by Decrease
If a value increases by a and then decreases by b, the net percentage change is: a−b−ab100
For equal increases and decreases of a%, the overall change is: −a2100
CAT 2026 Simple Interest and Compound Interest Practice Questions
Practise CAT-level Simple Interest and Compound Interest questions to strengthen formula application, calculation speed and accuracy.
1. The compound interest on a sum for two years at 20% per annum is ₹2,640. Find the simple interest on the same sum for three years at 15% per annum.
A. ₹2,700
B. ₹3,000
C. ₹3,300
D. ₹3,600
2. A sum of money amounts to ₹8,400 in 2 years and ₹9,240 in 4 years at simple interest. Find the principal.
A. ₹7,200
B. ₹7,560
C. ₹7,800
D. ₹8,000
3. A sum of Rs 10,000 is invested at 10% per annum compound interest for two years. What is the difference between the compound interest and simple interest?
A. Rs 90
B. Rs 100
C. Rs 110
D. Rs 120
4. A sum is invested at 20% per annum, compounded half-yearly, for 1.5 years. If the principal is Rs 10,000, what is the amount?
A. Rs 13,310
B. Rs 13,200
C. Rs 13,420
D. Rs 13,500
5. A machine depreciates by 10% in the first year and 20% in the second year. If its initial value is Rs 50,000, what is its value after two years?
A. Rs 36,000
B. Rs 36,500
C. Rs 37,000
D. Rs 38,000
Practise CAT Quant questions from 2021 to 2025 to understand recurring concepts and question patterns.
Download now: CAT Quant PYQs: Complete 5-Year Question Bank (2021-2025)
CAT 2026 SI and CI Important Question Types
These question types cover the common SI and CI approaches tested in CAT.
Question Type | Key Approach |
Direct SI | Use SI=PRT100 |
Direct CI | Calculate A first, then use CI=A−P |
SI vs CI | Use the difference shortcut |
Two-year difference | Use CI−SI=PR210000 |
Half-yearly CI | Halve the rate and double the time |
Quarterly CI | Divide the rate by 4 and multiply time by 4 |
Depreciation | Use A=P(1−R100)T |
Changing rates | Multiply the corresponding growth factors |
Successive changes | Apply percentage multiplication |
Unknown principal/rate/time | Rearrange the SI or CI formula |
Recognising the question type quickly can help candidates choose the right formula and save valuable time in CAT 2026.
Common Mistakes in CAT SI and CI Questions
Small interpretation errors can lead to incorrect answers even when the calculation is straightforward.
Using the SI formula when interest is compounded.
Forgetting to halve the rate for half-yearly compounding.
Forgetting to double the number of periods for half-yearly compounding.
Treating successive percentage changes as simple addition.
Confusing the final amount with the interest earned.
Applying the 2-year SI-CI shortcut to a question involving three or more years.
Past 10 years CAT Question Papers with Solutions
Ace CAT with confidence! Download the Past 10 Years' CAT Question Papers with detailed answers to understand exam trends, improve accuracy, and maximize your percentile.
Download Ebook
Build a stronger foundation in CAT Arithmetic with formulas, concepts, shortcuts and practice questions designed for candidates starting from the basics.
Download now: The CAT Arithmetic Hackbook: Zero Math Background? No Problem.
CAT 2026 SI and CI Quick Revision Formula Sheet
This quick revision sheet brings together the key SI and CI formulas needed for fast CAT 2026 revision.
Concept | Formula |
Simple Interest | SI=PRT100 |
Amount under SI | A=P+SI |
SI Amount | A=P(1+RT100) |
Compound Amount | A=P(1+R100)T |
Compound Interest | CI=A−P |
CI directly | CI=P[(1+R100)T−1] |
2-year CI-SI difference | CI−SI=PR210000 |
Depreciation | A=P(1−R100)T |
Half-yearly CI | A=P(1+R200)2T |
Quarterly CI | A=P(1+R400)4T |
Successive increases | a+b+ab100% |
Increase followed by decrease | a−b−ab100% |
Candidates can use these formulas to revise core concepts and solve SI and CI questions more efficiently.
Access a concise collection of important CAT Quant formulas for quick revision and efficient problem-solving.
Download now: CAT Important Formulas PDF
CAT 2026 SI and CI Preparation Strategy
A focused revision plan can make this topic easier to manage alongside the rest of Arithmetic.
Candidates should maintain an error log while practising. Recording the formula or calculation step responsible for each mistake can make revision more targeted.
CAT 2026 Mock Test
The CAT 2026 Free Mock Test gives candidates an opportunity to practise questions based on the actual exam format. Regular mock practice can help assess CAT preparation levels and improve time management.
Attempt Now: CAT 2026 Free Mock Test
How to Identify the Right SI or CI Formula in CAT
If the question asks... | Use... |
Interest on original principal | SI formula |
Interest on accumulated amount | CI formula |
Difference between SI and CI for 2 years | SI-CI shortcut |
Compounding twice a year | Half-yearly formula |
Compounding four times a year | Quarterly formula |
Value after depreciation | Depreciation formula |
Different rates in different periods | Multiply growth factors |
Unknown principal/rate/time | Rearrange SI formula |
Frequently Asked Questions (FAQs)
Q: Is Simple Interest and Compound Interest important for CAT?
A:
Yes. SI and CI are part of Arithmetic, an important area within CAT Quantitative Aptitude.
Q: What is the formula for Simple Interest in CAT?
A:
The formula is $SI=\frac{P\times R\times T}{100}$.
Q: What is the formula for Compound Interest?
A:
The compound amount is $A=P\left(1+\frac{R}{100}\right)^T$, and compound interest is $CI=A-P$.
Q: What is the shortcut for the difference between SI and CI for 2 years?
A:
For two years, the difference is $CI-SI=\frac{PR^2}{10000}$.
Q: How is half-yearly compound interest calculated?
A:
For half-yearly compounding, the rate becomes $\frac{R}{2}$ and the number of periods becomes $2T$. Hence, $A=P\left(1+\frac{R}{200}\right)^{2T}$.
Articles
Related Stories
|
Upcoming Mba Exams
Certifications By Top Providers
Explore Top Universities Across Globe
Popular Courses and Specializations
List of colleges accepting CAT
Browse Mba Colleges by State
Questions related to CAT
On Question asked by student community
Have a question related to CAT ?
Hello, CAT aur B-school entrance exams ke baare mein aap exam dates, eligibility, registration, exam pattern, syllabus, colleges ya admission process ki information dekh sakte hain. Aapki requirement ke according relevant details yahan mil sakti hain: https://bschool.careers360.com/exams
You can download the latest CAT syllabus from here:
Hey there,
For a B.Sc. with Chemistry, Botany and Zoology (CBZ), if the CAT application asks separately for:
- Degree Name: B.Sc.
- Graduation Stream: Science
- Discipline: enter/select Science if that is an available option.
If the Discipline dropdown has a more specific option such as “Biological Sciences,” “Life Sciences,” or “Zoology/Botany,”
Hey there,
Yes. With 2 years of work experience, you are eligible to target the regular 2-year MBA at IIM Calcutta as long as you have a bachelor's degree with at least 50% marks (45% for SC/ST/PwD). Work experience is not required for eligibility.
Which exam do you need?
For
Hey there,
For NIT Hamirpur MBA, the General-category CAT cutoff is not a fixed official percentile. NIT Hamirpur's 2026–27 admission process gives CAT a 10/10 weightage in the test component, followed by an interview; it accepts CAT, CMAT and MAT.
As a practical target, 80+ percentile is worth considering, while
Popular CAT Questions
Directions for question:
The bar-graph given below shows the foreign exchange reserves of Nepal (in million Rupees) from 2014 to 2021. Answer the following questions based on the graph :
Question:
What was the percentage increase (rounded to the nearest integer, if deemed necessary) in the foreign exchange reserves in
MBA/PGDM Admissions OPEN
Great Lakes - PGDM & PGPM Admissions 2027
ApplyGlobally Recognized by AACSB (US) & AMBA (UK) | 18 LPA Avg. CTC for PGPM 2026
IBSAT 2026-ICFAI Business School MBA/PGPM 2027
ApplyGateway to IBS Hyderabad & 8 other IBS campuses | Scholarships worth 10 CR
Goa Institute of Management PGDM Admissions 2027
ApplyAmong top 6% B-Schools globally to be accredited by AACSB | Highest Package-35 LPA
NMAT by GMAC 2026
ApplyTest centres are available in 70+ cities across India | 75,000+ aspirants apply for the NMAT exam | Accepted by 58+ institutions like NMIMS, KJSIM, ISB, SPJIMR and Great Lakes.
ISBR Business School PGDM Admissions 2027
Apply400+ Recruiters | Highest CTC 17.2 LPA | Average CTC 8 LPA | 92% Avg. Placements | Ranked as Platinum Institute | Awarded Best Business School of the Year
Woxsen University MBA Admissions 2027
ApplyApplication Open | Scholars’ Round Deadline: 14th Nov’26 | Earn upto 50% merit Scholarship + 10% for top performers | EFMD Accredited | AACSB & Business Graduates Association Member | Highest CTC 28 LPA
CAT Notifications
Never miss CAT update
Get timely CAT updates directly to your inbox. Stay informed!