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 70 of 118 pages

Question 691. A sum of Rs.1550 was lent partly at 5% and partly at 8% simple interest. The total interest received after 3 years is Rs.300. The ratio of money lent at 5% to that at 8% is :

8 : 5
5 : 8
16 : 15
31 : 6

Discuss Question

Answer: Option C. -> 16 : 15
Answer: (c)Using Rule 1Simple Interest (S.I.)= ${\text"Principal × Rate × Time"/100$ orS.I. = ${\text"P × R × T"/100$P = ${\text"S.I." × 100}/\text"R × T"$, R = ${\text"S.I." × 100}/\text"P × T"$, T = ${\text"S.I." × 100}/\text"P × R"$ A = P + S.I. or S.I. = A - P

Question 692. With a given rate of simple interest, the ratio of principal and amount for a certain period of time is 4 : 5. After 3 years, with the same rate of interest, the ratio of the principal and amount becomes 5 : 7. The rate of interest is

Discuss Question

Answer: Option D. -> 5%
Answer: (d)Using Rule 1,Case-I,Interest = 5x - 4x = x$x = {4x × R × T}/100$T = $25/R$ yearsCase-II,T = $25/R + 3 = ({25 + 3R}/R)$ yearsSI = 7 y - 5y = 2y$2y = {5y × R × (25 + 3R)}/{R × 100}$40 = 25 + 3R3R = 40 –25 = 15 %R = $15/3$ = 5%

Question 693. Ratio of the principal and the amount after 1 year is 10:12. Then the rate of interest per annum is :

Discuss Question

Answer: Option C. -> 20%
Answer: (c)Using Rule 1,$\text"Principal"/\text"Amount" = 10/12$$\text"Amount"/ \text"Principal" = \text"Principal + interest"/ \text"Principal" = 12/10$1 + $\text"Interest"/ \text"Principal" = 12/10$$\text"Interest"/ \text"Principal" = 2/10 = 1/5$Rate = $1/5$ × 100 = 20%

Question 694. If the ratio of principal and the simple interest for 5 years is 10 : 3, then the rate of interest is :

Discuss Question

Answer: Option A. -> 6%
Answer: (a)Using Rule 1,$\text"Principal"/ \text"Interest" = 10/3$$\text"Interest"/ \text"Principal" = 3/10$Rate = $\text"S.I. × 100"/ \text"Principal × Time"$= $3/10 × 100/5$ = 6% per annum

Question 695. A person invests money in three different schemes for 6 years, 10 years and 12 years at 10 per cent, 12 per cent and 15 per cent simple interest respectively. At the completion of each scheme, he gets the same interest. The ratio of his investment is

2 : 3 : 4
6 : 3 : 2
3 : 4 : 2
3 : 4 : 6

Discuss Question

Answer: Option B. -> 6 : 3 : 2
Answer: (b)Using Rule 1,P1 : P2 : P3 = $1/{r_1t_1} : 1/{r_2t_2} : 1/{r_3t_3}$= $1/{6 × 10} : 1/{10 × 12} : 1/{12 × 15}$= $1/60 : 1/120 : 1/180$ = 6 : 3 : 2

Question 696. If ratio of principal and simple interest for 1 year is 25 : 1, then the rate of interest is

Discuss Question

Answer: Option B. -> 4%
Answer: (b)Using Rule 1,Principal : Interest = 25 : 1Interest : Principal = 1 : 25Rate = $\text"S.I. × 100"/ \text"Principal × Time"$= $1/25$ × 100 = 4% per annum

Question 697. The compound interest on Rs.10,000 in 2 years at 4% per annum, the interest being compounded half-yearly, is :

Rs.828. 82
Rs.636.80
Rs.912. 86
Rs.824.32

Discuss Question

Answer: Option D. -> Rs.824.32
Answer: (d)Using Rule 1,A = 10,000$(1 + 2/100)^4$=10,000$(51/50)^4$ =10824.3216Interest = 10,824.3216 - 10,000= Rs.824.32

Question 698. A man borrows Rs.21000 at 10% compound interest. How much he has to pay annually at the end of each year, to settle his loan in two years ?

Rs.12300
Rs.12000
Rs.12200
Rs.12100

Discuss Question

Answer: Option D. -> Rs.12100
Answer: (d)If each instalment be x, then Present worth of first instalment= $x/{1 + 10/100} = {10x}/11$= Present worth of second instalment= $x/(1 + 10/100)^2 = 100/121x$$10/11x + 100/121x$ = 21000${110x + 100x}/121 = 21000$210x = 21000 × 121$x = {21000 × 121}/210$ = Rs.12100 Using Rule 9,If a sum 'P' is borrowed at r% annual compound interest which is to be paid in 'n' equal annual installments including interest, then(i) For n = 2, Each annual installment= $p/{(100/{100 + r}) + (100/{100 + r})^2$(ii) For n = 3, Each annual installment= $p/{(100/{100 + r}) + (100/{100 + r})^2 + (100/{100 + r})^3$

Question 699. A certain sum, invested at 4% per annum compound interest, compounded half yearly, amounts to Rs.7,803 at the end of one year. The sum is

Rs.7,700
Rs.7,000
Rs.7,500
Rs.7,200

Discuss Question

Answer: Option C. -> Rs.7,500
Answer: (c)Using Rule 1,Let the sum be P.As, the interest is compounded half-yearly,R = 2%, T = 2 half yearsA = P$(1 + R/100)^T$7803 = P$(1 + 2/100)2$7803 = $(1 + 1/50)^2$7803 = P$× 51/50 × 51/50$P = ${7803 × 50 × 50}/{51 × 51}$ = Rs.7500

Question 700. In how many years will Rs.2,000 amounts to Rs.2,420 at 10% per annum compound interest?

1$1/2$ years
3 years
2 years
2$1/2$ years

Discuss Question

Answer: Option C. -> 2 years
Answer: (c)Using Rule 1,According to question,2420 = 2000$(1 + 10/100)^t$$2420/2000 = (11/10)^t$or $(11/10)^t = 121/100$or, $(11/10)^t = (11/10)^2$t = 2 years