Practice Questions
Concept Explanation
For the same principal and rate, compound interest exceeds simple interest because CI earns interest on interest.
Key Formulas
- 2 years: Difference = P(R/100)^2
- 3 years: Difference = P(R/100)^2 × (3 + R/100)
Example
P = Rs. 10,000, R = 10%, 2 years. Difference = 10000 × (0.1)^2 = Rs. 100.
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Q1 Easy
CI − SI on Rs. 10,000 at 10% for 2 years is:
ExplanationDifference = 10000 × (0.1)^2 = Rs. 100. -
Q2 Easy
Difference on Rs. 20,000 at 10% for 2 years is:
ExplanationDifference = 20000 × 0.01 = Rs. 200. -
Q3 Medium
Difference on Rs. 5,000 at 20% for 2 years is:
ExplanationDifference = 5000 × 0.04 = Rs. 200. -
Q4 Easy
Difference on Rs. 10,000 at 5% for 2 years is:
ExplanationDifference = 10000 × 0.0025 = Rs. 25. -
Q5 Medium
Difference on Rs. 16,000 at 5% for 2 years is:
ExplanationDifference = 16000 × 0.0025 = Rs. 40. -
Q6 Medium
Difference on Rs. 10,000 at 10% for 3 years is:
ExplanationDifference = 10000 × 0.01 × 1.1 = Rs. 110. -
Q7 Easy
Difference on Rs. 8,000 at 10% for 2 years is:
ExplanationDifference = 8000 × 0.01 = Rs. 80.
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Q8 Medium
Difference on Rs. 25,000 at 10% for 2 years is:
ExplanationDifference = 25000 × 0.01 = Rs. 250. -
Q9 Hard
If difference for 2 years at 10% is Rs. 100, principal is:
ExplanationP = 100/(0.1^2) = Rs. 10,000. -
Q10 Hard
Difference on Rs. 15,000 at 10% for 3 years is:
ExplanationDifference = 15000 × 0.01 × 1.1 = Rs. 165. -
Q11 Hard
Difference on Rs. 12,000 at 5% for 3 years is:
ExplanationDifference = 12000 × 0.0025 × 1.05 = Rs. 31.50. -
Q12 Medium
Difference on Rs. 10,000 at 20% for 2 years is:
ExplanationDifference = 10000 × 0.04 = Rs. 400. -
Q13 Easy
Difference on Rs. 9,000 at 10% for 2 years is:
ExplanationDifference = 9000 × 0.01 = Rs. 90. -
Q14 Hard
Difference on Rs. 20,000 at 5% for 3 years is:
ExplanationDifference = 20000 × 0.0025 × 1.05 = Rs. 52.50.
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DS1 Easy
What is CI − SI for 2 years?
Statement IPrincipal is Rs. 10,000 at 10% per annum.
Statement IITime is 2 years.
ExplanationNeed P, R and T = 2 together. Difference = Rs. 100. -
DS2 Medium
What is the principal?
Statement ICI − SI for 2 years at 10% is Rs. 100.
Statement IIRate is 10% and time is 2 years.
ExplanationStatement I alone gives P = Rs. 10,000.
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DS3 Medium
What is CI − SI for 3 years?
Statement IP = Rs. 10,000, R = 10%.
Statement IITime is 3 years.
ExplanationTogether: difference = Rs. 110. -
DS4 Hard
Is the difference greater than Rs. 200?
Statement IP = Rs. 25,000 at 10% for 2 years.
Statement IIRate is 10%.
ExplanationStatement I: difference = Rs. 250, which is greater than Rs. 200.