Simple & Compound Interest(Quantitative Aptitude > Interest ) Questions and answers for exam Preparation

Quantitative Aptitude > Interest

SIMPLE & COMPOUND INTEREST MCQs

Compound Interest, Simple Interest, Interest (combined)

Total Questions : 1171 | Page 74 of 118 pages

Question 731. On what sum of money will the difference between S.I and C.I for 2 years at 5% per annum be equal to 25 ?

9000
10,000
9,500
10,500

Discuss Question

Answer: Option B. -> 10,000
Answer: (b)Using Rule 6,Difference = ${PR^2}/10000$25 = ${P × 5 × 5}/10000$P = Rs.10000

Question 732. The difference between the compound interest and simple interest on 10,000 for 2 years is 25. The rate of interest per annum is

Discuss Question

Answer: Option B. -> 5%
Answer: (b)Using Rule 6,Difference = ${PR}^2/10000$25 = ${10000 × R^2}/10000$ ⇒ R = 5%

Question 733. If the difference between the compound interest, compounded every six months, and the simple interest on a certain sum of money at the rate of 12% per annum for one year is 36, the sum is :

9,000
10,000
15,000
12,000

Discuss Question

Answer: Option B. -> 10,000
Answer: (b)Easy TrickAs the interest was compounded half-yearly,we changed r to $r/2$ and t to 2t.T = 1 year & R 6%Sum = ${36 × 100 × 100}/{6 × 6}$ = Rs.10000

Question 734. The difference between simple and compound interests on a sum of money at 4% per annum for 2 years is 8. The sum is

5,000
400
4,000
800

Discuss Question

Answer: Option A. -> 5,000
Answer: (a)Using Rule 6,Let the sum be x.When difference between the compound interest and simple interest on a certain sum of money for 2 years at r% rate is x, then the sum is given by:Sum = Difference × $(100/\text"Rate")^2$= Rs.8 × $(100/4)^2$= Rs.8 × 25 × 25 = Rs.5000

Question 735. The difference between compound and simple interest on a certain sum for 3 years at 5% per annum is Rs. 122. The sum is

10,000
16,000
12,000
15,000

Discuss Question

Answer: Option B. -> 16,000
Answer: (b)Using Rule 6,Let the difference between CI and SI on a certain sum for 3 years at r % be x,then the sum v= ${\text"Difference" × (100)^3}/{r^2(300 + r)}$= ${122 × {100}^3}/{25(300 + 5)}$= $122000000/{25 × 305}$ = Rs.16000

Question 736. The difference between the compound interest and simple interest on a certain sum for 2 years at 10% per annum is 300. Find the sum.

30,500
31,000
30,000
31,500

Discuss Question

Answer: Option C. -> 30,000
Answer: (c)Using Rule 6,Difference = ${PR^2}/10000$300 = ${P × 10 × 10}/10000$P = 300 × 100 = Rs.30000

Question 737. What is the difference between compound interest on 5,000 for 1 1 2 years at 4% per annum according as the interest is compounded yearly or halfyearly?

4.80
2.04
8.30
3.06

Discuss Question

Answer: Option D. -> 3.06
Answer: (d)Compound Interest (when compounded yearly)= $5000(1 + 4/100)^(1.5) - 5000$= $5000(26/25)^(1.5) - 5000$= 5302.9805 - 5000 = Rs.302.9805C.I. (When compounded halfyearly).= $5000(1 + 2/100)^3 - 50000$= 5306.04 - 5000 = Rs.306.04Required difference= Rs.(306.04 - 302.9805)= Rs.3.059 = Rs.3.06

Question 738. The difference between the compound interest (compounded annually) and the simple interest on a sum of 1000 at a certain rate of interest for 2 years is 10. The rate of interest per annum is :

Discuss Question

Answer: Option C. -> 10%
Answer: (c)When difference between the compound interest and simple interest on a certain sum of money for 2 years at r% rate is x, thenx = Sum$(r/100)^2$10 = 1000$(r/100)^2$$(r/100)^2 = 10/1000$$r/100 = √{1/100} = 1/10$r = $100/10$ = 10%Using Rule 6,Here, C.I. - S.I. = Rs.10, R = ?, T= 2 years, P = Rs.1000C.I. - S.I. = P$(R/100)^2$10 = 1000$(R/100)^2$10 = 1000$ × R/100 × R/100$$R^2$ = 100R = $√{100}$ = 10%

Question 739. The difference between simple interest and compound interest of a certain sum of money at 20% per annum for 2 years is 48. Then the sum is

2, 000
1,000
1, 500
1, 200

Discuss Question

Answer: Option D. -> 1, 200
Answer: (d)Using Rule 6,Difference of two years= P$(r^2/10000)$48 = P$(400/10000)$48 = $P/25$P = 48 × 25 = Rs.1200

Question 740. The difference between compound interest (compounded annually) and simple interest on a certain sum of money at 10% per annum for 2 years is 40. The sum is :

3200
4000
4200
3600

Discuss Question

Answer: Option B. -> 4000
Answer: (b)Let the principal be x.Compound interest= P$[(1 + R/100)^t - 1]$= $x[(1 + 10/100)^2 - 1]$= $x[(1.1)^2 - 1]$= x (1.21 - 1) = 0.21xSI = ${x × 2 × 10}/100 = x/5 = 0.2x$According to the question,0.21x - 0.2x = 40$0.01x = 40 ⇒ x = 40/{0.01}$ = Rs.4000Using Rule 6,Here, C.I. - S.I. = Rs.40, R = 10%, T = 2 years, P = ?C.I. - S.I. = P$(R/100)^2$40 = P$(10/100)^2$ ⇒ P = Rs.4000