Compound Interest
8 questions · Hard
Compound interest is paid on the principal plus the interest already earned. Amount = P × (1 + R/100)^T, and CI = amount − principal.
💡 Quick tricks
- For 2 years, CI − SI = P × (R/100)².
- At 10% a year, the amount grows by 1.1 times each year: 1.21 times after 2 years.
- Half-yearly compounding: halve the rate and double the number of periods.
🎯 Try it yourself
Tap an answer. You'll see if it's right, and why. Easy ones come first.
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Q1Hard
Compound interest on ₹13,800 for 2 years at 10% a year?
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Answer: D. ₹2,898
💡 Amount = 13,800 × (1 + 10/100)² = ₹16,698, so CI = ₹2,898.
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Q2Hard
Compound interest on ₹1,700 for 2 years at 20% a year?
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Answer: C. ₹748
💡 Amount = 1,700 × (1 + 20/100)² = ₹2,448, so CI = ₹748.
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Q3Hard
Compound interest on ₹21,600 for 2 years at 15% a year?
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Answer: B. ₹6,966
💡 Amount = 21,600 × (1 + 15/100)² = ₹28,566, so CI = ₹6,966.
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Q4Hard
Compound interest on ₹7,100 for 2 years at 10% a year?
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Answer: C. ₹1,491
💡 Amount = 7,100 × (1 + 10/100)² = ₹8,591, so CI = ₹1,491.
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Q5Hard
Compound interest on ₹15,000 for 2 years at 12% a year?
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Answer: D. ₹3,816
💡 Amount = 15,000 × (1 + 12/100)² = ₹18,816, so CI = ₹3,816.
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Q6Hard
Compound interest on ₹18,800 for 2 years at 20% a year?
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Answer: C. ₹8,272
💡 Amount = 18,800 × (1 + 20/100)² = ₹27,072, so CI = ₹8,272.
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Q7Hard
Compound interest on ₹12,000 for 2 years at 5% a year?
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Answer: D. ₹1,230
💡 Amount = 12,000 × (1 + 5/100)² = ₹13,230, so CI = ₹1,230.
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Q8Hard
Compound interest on ₹30,000 for 2 years at 20% a year?
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Answer: C. ₹13,200
💡 Amount = 30,000 × (1 + 20/100)² = ₹43,200, so CI = ₹13,200.
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