Skip to main content
Chapter 3 of 28
Flashcards

Compound Interest (Using Formula)

ICSE · Class 9 · Mathematics

Flashcards for Compound Interest (Using Formula) — ICSE Class 9 Mathematics. Quick Q&A cards covering key concepts, definitions, and formulas.

44 questions20 flashcards5 concepts
20 Flashcards
Card 1Basic Formula

What is the formula for Amount when interest is compounded yearly?

Answer

A = P(1 + r/100)ⁿ Where: A = Amount P = Principal r = Rate of interest per annum n = Number of years This formula helps us calculate the total amount after compound interest without finding CI separ

Card 2Basic Formula

How do you calculate Compound Interest directly using a formula?

Answer

C.I. = P[(1 + r/100)ⁿ - 1] Or alternatively: C.I. = A - P The first formula directly gives compound interest without calculating amount first. The second requires finding amount first and then subtr

Card 3Basic Calculations

Calculate the amount on ₹5,000 for 2 years at 8% compounded annually.

Answer

Given: P = ₹5,000, n = 2 years, r = 8% Using A = P(1 + r/100)ⁿ A = ₹5,000(1 + 8/100)² A = ₹5,000(1.08)² A = ₹5,000 × 1.1664 A = ₹5,832 Therefore, Amount = ₹5,832

Card 4Variable Rates

What formula is used when rates for successive years are different?

Answer

A = P(1 + r₁/100)(1 + r₂/100)(1 + r₃/100)... Where: r₁%, r₂%, r₃%... are rates for 1st, 2nd, 3rd year respectively Example: For 3 years with rates 10%, 12%, 15%: A = P(1 + 10/100)(1 + 12/100)(1 + 15

Card 5Inverse Problems

How do you find the Principal when Amount, rate, and time are given?

Answer

From A = P(1 + r/100)ⁿ We get: P = A / (1 + r/100)ⁿ Example: If A = ₹6,050, r = 10%, n = 2 years P = ₹6,050 / (1 + 10/100)² P = ₹6,050 / (1.1)² P = ₹6,050 / 1.21 P = ₹5,000

Card 6Inverse Problems

How do you find the rate percent when Principal, Amount, and time are given?

Answer

From A = P(1 + r/100)ⁿ We get: (1 + r/100) = (A/P)^(1/n) Therefore: r = 100[(A/P)^(1/n) - 1] Example: If P = ₹8,000, A = ₹9,680, n = 2 years (1 + r/100) = (9,680/8,000)^(1/2) = (1.21)^(1/2) = 1.1 S

Card 7Inverse Problems

How do you find the time when Principal, Amount, and rate are given?

Answer

From A = P(1 + r/100)ⁿ We get: (1 + r/100)ⁿ = A/P Solve by comparing both sides to find n. Example: If P = ₹4,000, A = ₹4,840, r = 10% (1.1)ⁿ = 4,840/4,000 = 1.21 = (1.1)² Therefore, n = 2 years

Card 8CI vs SI

What is the formula for difference between CI and SI for 2 years?

Answer

For 2 years: C.I. - S.I. = P × r² / (100)² This formula is very useful for solving problems where the difference between CI and SI is given. Example: If difference is ₹25 and rate is 5% 25 = P × (5)

+12 more flashcards available

Practice All

Get detailed flashcards for Compound Interest (Using Formula)

Super Tutor gives you interactive content for every chapter of ICSE Class 9 Mathematics — summaries, quizzes, flashcards, and more.

Try Super Tutor — It's Free

Frequently Asked Questions

What are the important topics in Compound Interest (Using Formula) for ICSE Class 9 Mathematics?

Compound Interest (Using Formula) covers several key topics that are frequently asked in ICSE Class 9 board exams. Focus on the core concepts listed on this page and practise related questions to build confidence.

Start by understanding all key concepts. Practise previous year questions from this chapter. Revise formulas and definitions regularly. Use flashcards for quick revision before the exam.

There are 20 flashcards for Compound Interest (Using Formula) covering key definitions, formulas, and concepts. Use them daily for 10–15 minutes for best results.

Sources & Official References

Content is aligned to the official syllabus. Refer to the board website for the latest curriculum.