Quantitative Aptitude

Simple and Compound Interest

3,394 Questions
All Simple interest and its inverse forms 768 Compound interest with annual compounding 742 Simple-interest growth and split sums 626 Difference between compound and simple interest 479 Half-yearly and quarterly compounding 252 Changing rates and fractional years 201 Installments (CI based) 190 Ratio of principal to interest 118 Population growth and depreciation 16

Simple and Compound Interest Questions

Multiple choice

A borrowed two loans altogether of Rs. 14000 from B and C. B claimed 12% simple interest per annum while C claimed 14% per annum. The total interest paid by A in one year was Rs. 1800. The amount A borrowed A ने B और C से कुल रू. 14000 के दो ऋण लिए। B ने 12% प्रतिवर्ष का साधारण ब्याज लिया और C ने 14% प्रतिवर्ष लिया। A द्वारा एक वर्ष में दिया गया कुल ब्याज रू.1800 था। तो, A ने लिए थे ।

  1. Rs. 8000 from C/C से रू. 8000

  2. Rs. 8000 from B /B से रू. 8000

  3. Rs. 7400 from C / C से रू. 7400

  4. Rs. 7400 from B/C से रू. 7400
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Let amount from B = x, from C = 14000-x. Interest from B at 12% = 0.12x, from C at 14% = 0.14(14000-x) = 1960 - 0.14x. Total: 0.12x + 1960 - 0.14x = 1800. Solving: -0.02x = -160, x = 8000. So Rs. 8000 from B, Rs. 6000 from C. Verify: 8000×0.12 = 960, 6000×0.14 = 840, total = 1800.

Multiple choice

The difference between the simple interest and the compound interest on Rs. 6000 for 1 year at 10% per annum, reckoned half-yearly is- 6000 रू. पर 10% प्रतिवर्ष की दर से अर्द्धवार्षिक संयोजित होने के अनुसार, 1 वर्ष में साधारण और चक्रवृद्धि ब्याज का अन्तर होगा?

  1. 10

  2. 25

  3. 15

  4. 12
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

SI = 6000 × 10/100 = 600. CI at half-yearly: P = 6000, R = 5% per half-year, n = 2. CI = 6000 × 1.05² - 6000 = 6000 × 1.1025 - 6000 = 6150 - 6000 = 615. Difference = 615 - 600 = 15.

Multiple choice

On What sum does the difference between the compound interest and the simple interest for 3 years at 10% is Rs. 310? किस धनराशि पर 10% वार्षिक की दर से 3 वर्ष के साधारण ब्याज और चक्रवृद्धि ब्याज का अन्तर 310 रू. होगा?

  1. Rs. 11000

  2. Rs. 10000

  3. Rs. 15000

  4. Rs. 12000
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Difference between CI and SI for 3 years at 10% = P × (r/100)² × (3 + r/100). 310 = P × (10/100)² × 3.1. 310 = P × 0.01 × 3.1. P = 310/(0.031) = 10000.

Multiple choice

The simple interest on Rs. 12000 in 3 years at the rate of x% per annum equals to the simple interest on Rs. 15000 at the rate of 12% per annum in 2 years. The value of x is - 12000 रू. पर x% प्रतिवर्ष साधारण ब्याज की दर से 3 वर्षो का साधारण ब्याज, 15000 रू. पर 12% प्रति वर्ष साधारण ब्याज की दर से 2 वर्षो के साधारण ब्याज के बराबर है। x का मान क्या है?

  1. 6%

  2. 8%

  3. 9%

  4. 10%
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Setting the simple interests equal: 12000×x×3 = 15000×12×2. This gives 36000x = 360000, so x = 10. The simple interest on Rs. 12000 at 10% for 3 years (SI = 12000×10×3/100 = Rs. 3600) equals the simple interest on Rs. 15000 at 12% for 2 years (SI = 15000×12×2/100 = Rs. 3600). Option D is correct.

Multiple choice

At what percent per annum will Rs. 2000/- amounts to Rs. 2420/- in 2 years if the interest is compounded annually? किस प्रतिशत वार्षिक ब्याज दर से रु 2000, 2 वर्षों में 2420 रु हो जाएगा यदि ब्याज चक्रवृद्धि वार्षिक हो ?

  1. 20 %

  2. 15 %

  3. 10 %

  4. 9 %
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Using compound interest formula A = P(1+r)^t: 2000(1+r)^2 = 2420. Solving gives (1+r)^2 = 1.21, so 1+r = 1.1, hence r = 10% per annum.

Multiple choice

At what percent per annum will Rs 3000 amount to Rs. 3993 in 3 years if the interest is compounded annually? किस वार्षिक प्रतिशत ब्याज की दर से 3000 रूपए का मिश्रधन 3 वर्षों में 3993 रूपए हो जाएगा, यदि चक्रवृद्धि ब्याज वार्षिक संयोजित किया जाता है?

  1. 5%

  2. 10%

  3. 7%

  4. 12.5%
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Using A = P(1 + r/100)³: 3993 = 3000(1 + r/100)³, so (1 + r/100)³ = 1.331. Taking cube root: 1 + r/100 = 1.1, thus r = 10%. Verify: 3000 × 1.1³ = 3000 × 1.331 = 3993. Option B is correct.

Multiple choice

What would be the compound interest accrued on an amount of Rs 8000 at the rate of 15% p.a. in three years? 8000 रू. पर 15% की वार्षिक दर से तीन वर्षो का चक्रवृद्धि ब्याज क्या होगा?

  1. Rs 4283

  2. Rs 4051

  3. Rs 4167

  4. Rs 4325
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Principal = 8000, Rate = 15%, Time = 3 years. Amount after 1 year = 8000 × 1.15 = 9200. After 2 years = 9200 × 1.15 = 10580. After 3 years = 10580 × 1.15 = 12167. CI = 12167 - 8000 = Rs 4167. Option C is correct. Alternatively: CI = P[(1 + r/100)³ - 1] = 8000[1.15³ - 1] = 8000 × 0.520875 = Rs 4167.

Multiple choice

A man took a loan from a bank at the rate of 12% per annum at simple interest. After 3 years he had to pay Rs. 5400 as interest only for the period. The principal amount borrowed by him was - एक व्यक्ति ने एक बैंक से साधारण ब्याज की 12% वार्षिक दर पर ऋण लिया। तीन वर्ष के पश्चात उसने 5400 रू. उस समयावधि के लिए केवल ब्याज के रूप में लौटाए । ऋणस्वरूप ली गयी मूल धनराशि थी।

  1. Rs./रू. 2000

  2. Rs./रू. 10000

  3. Rs./रू. 20000

  4. Rs./रू. 15000
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Simple Interest = Principal × Rate × Time / 100. Given: SI = Rs. 5400, Rate = 12%, Time = 3 years. So 5400 = P × 12 × 3 / 100 = 36P/100. Therefore P = 5400 × 100/36 = Rs. 15,000. Option D is correct.

Multiple choice

A sum is invested at compound interest payable annually. The interest in two successive years was Rs.900 and Rs.981. Find the sum. एक धनराशि वार्षिक चक्रवृद्धि ब्याज पर निवेश की जाती है । दो क्रमागत वर्षों में ब्याज 900 रू. और 981 रू. है । धनराशि ज्ञात कीजिए ।

  1. Rs. 10000

  2. Rs9000

  3. Rs. 12000

  4. Rs. 9900
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

When interest increases from Rs.900 to Rs.981, the rate of interest = (981-900)/900 × 100 = 9%. If compound interest for first year is Rs.900 at 9%, then principal = 900 ÷ 0.09 = Rs.10000. This uses the property that in compound interest, the difference between successive years gives the rate.

Multiple choice

The difference between the interests received from two different banks on Rs. 500 for two years is Rs. 2.50. The difference between their rates is- यदि 500 रू. पर दो भिन्न-भिन्न बैंकों से प्राप्त दो वर्ष के ब्याज के बीच अन्तर 2.50 रू. है, तो उनके दरों में अन्तर कितना है?

  1. 1%

  2. 1.5%

  3. 0.50%

  4. 0.25%
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

For simple interest, SI = P × R × T. The difference in interests is: 500 × (r1 - r2) × 2 = 2.50. Solving: r1 - r2 = 2.50 ÷ (500 × 2) = 0.0025 = 0.25%. This is option D. The principal and time cancel out when finding the rate difference, leaving only the rate.

Multiple choice

A person invests his money in two schemes A and B equally. In scheme A he invested money for 3 years at 5% and in scheme B he invested his money for 2 years at 10% of simple interest. If at the end he get total interest of Rs.7000. Find the total amount he invested?

  1. 20000

  2. 25000

  3. 30000

  4. 40000
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let the total amount invested be 2x. So x in each scheme. Scheme A interest: x * 5% * 3 = 0.15x. Scheme B interest: x * 10% * 2 = 0.20x. Total interest = 0.15x + 0.20x = 0.35x = 7000. Therefore x = 7000/0.35 = 20000. Total investment = 2x = 40000. Answer D is correct.