Simple interest
Ten quantitative aptitude questions, each marked as you answer.
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What is the simple interest on ₹38,500 at 8% per annum for 4 years?
Answer and working
Answer D
SI = P × R × T / 100 = 38,500 × 8 × 4 / 100 = ₹12,320.
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A sum of money at simple interest amounts to ₹34,800 in 2 years and to ₹39,600 in 4 years. What is the sum?
Answer and working
Answer B
Interest for 2 years = 39,600 − 34,800 = ₹4,800, so ₹2,400 a year. Interest for 2 years = ₹4,800. Sum = 34,800 − 4,800 = ₹30,000.
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The simple interest on a sum for 2 years at 9% per annum is ₹9,000. What is the sum?
Answer and working
Answer A
P = SI × 100 / (R × T) = 9,000 × 100 / (9 × 2) = ₹50,000.
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What is the simple interest on ₹40,000 at 15% per annum for 4 years?
Answer and working
Answer D
SI = P × R × T / 100 = 40,000 × 15 × 4 / 100 = ₹24,000.
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What is the simple interest on ₹40,000 at 7% per annum for 5 years?
Answer and working
Answer C
SI = P × R × T / 100 = 40,000 × 7 × 5 / 100 = ₹14,000.
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A sum of money at simple interest amounts to ₹30,800 in 2 years and to ₹35,750 in 5 years. What is the sum?
Answer and working
Answer D
Interest for 3 years = 35,750 − 30,800 = ₹4,950, so ₹1,650 a year. Interest for 2 years = ₹3,300. Sum = 30,800 − 3,300 = ₹27,500.
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A sum of money doubles itself in 20 years at simple interest. What is the rate of interest per annum?
Answer and working
Answer D
The interest earned is 1 times the principal in 20 years. Rate = 1 × 100 / 20 = 5%.
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A sum of money becomes three times itself in 10 years at simple interest. What is the rate of interest per annum?
Answer and working
Answer A
The interest earned is 2 times the principal in 10 years. Rate = 2 × 100 / 10 = 20%.
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A sum of money becomes four times itself in 15 years at simple interest. What is the rate of interest per annum?
Answer and working
Answer C
The interest earned is 3 times the principal in 15 years. Rate = 3 × 100 / 15 = 20%.
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What is the simple interest on ₹42,500 at 5% per annum for 4 years?
Answer and working
Answer A
SI = P × R × T / 100 = 42,500 × 5 × 4 / 100 = ₹8,500.
More quantitative aptitude: Percentages, Profit, loss and discount, Compound interest, Ratio and proportion, Averages, Problems on ages.