Sail E0 Webinar

Quantitative Aptitude > Interest

COMPOUND INTEREST MCQs

Total Questions : 262 | Page 6 of 27 pages
Question 51. A sum of money is paid back in two annual instalments of Rs. 17, 640 each, allowing 5% compound interest compounded annually. The sum borrowed was
  1.    Rs.32,400
  2.    Rs.32,800
  3.    Rs.32,000
  4.    Rs.32,200
 Discuss Question
Answer: Option B. -> Rs.32,800
Answer: (b)Using Rule 9(i),Sum borrowed = Present worth of Rs.17640 due 1 year hence + Present worth of Rs.17640 due 2 years hence= Rs.$(17640/{(1 + 5/100)} + 17640/{(1 + 5/100)^2})$= Rs.$(17640 × 20/21 + 17640 × 20/21 × 20/21)$= Rs.(16800 + 16000) = Rs.32800
Question 52. The income of a company increases 20% per year. If the income is Rs. 26,64,000 in the year 2012, then its income in the year 2010 was :
  1.    Rs.21,20,000
  2.    Rs.28,55,000
  3.    Rs.28,20,000
  4.    Rs.18,50,000
 Discuss Question
Answer: Option D. -> Rs.18,50,000
Answer: (d)Using Rule 1,Let the income of company in 2010 be Rs.PAccording to the question,A = P$(1 + R/100)^T$2664000 = P$(1 + 20/100)^2$2664000 = P$(1 + 1/5)^2$2664000 = P × $(6/5)^2$P = ${2664000 × 5 × 5}/{6 × 6}$ = Rs.1850000
Question 53. On a certain sum of money, the simple interest for 2 years is Rs.350 at the rate of 4% per annum. If it was invested at compound interest at the same rate for the same duration as before, how much more interest would be earned ?
  1.    Rs.35
  2.    Rs.3.50
  3.    Rs.14
  4.    Rs.7
 Discuss Question
Answer: Option D. -> Rs.7
Answer: (d)Principal = $\text"S.I. × 100"/\text"Time × Rate"$= ${350 × 100}/{2 × 4}$ = Rs.4375Difference = ${PR^2}/10000$= ${4375 × 4 × 4}/10000$ = Rs.7
Question 54. The compound interest on a certain sum of money at a certain rate for 2 years is Rs.40.80 and the simple interest on the same sum is Rs.40 at the same rate and for the same time. The rate of interest is
  1.    5% per annum
  2.    2% per annum
  3.    4% per annum
  4.    3% per annum
 Discuss Question
Answer: Option C. -> 4% per annum
Answer: (c)Let the principal be P and rate of interest be r per cent per annum. Then,C. I = P$[(1 + r/100)^2 - 1]$40.80 = P$[(1 + r/100)^2 - 1]$...(i)S.I. = ${P.r.t}/100 ⇒ 40 = {Pr × 2}/100$ ...(ii)${40.80}/40 = P[(1 + r/100)^2 - 1]/{{2Pr}/100}$ ⇒ 1.02= $100/{2r}[1 + r^2/10000 + {2r}/100 - 1]$1.02 = $r/200$ +1$r/200$ = 1.02 - 1r = 0.02 × 200 = 4% per annum.Using Rule 10,Here, C.I. = Rs.40.80, S.I. = Rs.40, R = ?C.I.= S.I.$(1 + R/200)$40.80 = 40$(1 + R/200)$$4080/4000 = 1 + R/200$$408/400 = {200 + R}/200$408 = 400 + 2R2R = 8 ⇒ R = 4%
Question 55. If the compound interest on a sum of money for 3 years at the rate of 5% per annum is Rs.252.20, the simple interest on the same sum at the same rate and for the same time is
  1.    Rs.250
  2.    Rs.220
  3.    Rs.245
  4.    Rs.240
 Discuss Question
Answer: Option D. -> Rs.240
Answer: (d)Using Rule 1,If A = Amount, P = Principal, r = Rate of Compound Interest (C.I.), n = no. of years then,A=P$(1 + r/100)^n$, C.I. = A - PC.I. = P$[(1 + r/100)^n - 1]$
Question 56. The compound interest on a certain sum of money at a certain rate per annum for two years is Rs.2,050, and the simple interest on the same amount of money at the same rate for 3 years is Rs.3, 000. Then the sum of money is
  1.    Rs.25, 000
  2.    Rs.20,000
  3.    Rs.21,000
  4.    Rs.18,000
 Discuss Question
Answer: Option B. -> Rs.20,000
Answer: (b)Using Rule 6,The difference between C.I. and S.I. on a sum 'P' in 2 years at the rate of R% rate of compound interest will beC.I - S.I. = P$(R/100)^2 = {S.I. × R}/200$ For 3 years, C.I. - S.I. = P$(R/100)^2 × (3 + R/100)$
Question 57. The compound interest on a certain sum of money invested for 2 years at 5% per annum is Rs.328. The simple interest on the sum, at the same rate and for the same period will be
  1.    Rs.287
  2.    Rs.320
  3.    Rs.300
  4.    Rs.308
 Discuss Question
Answer: Option B. -> Rs.320
Answer: (b)Let the principal be P.C.I. = P$[(1 + R/100)^T - 1]$328 = P$[(1 + 5/100)^2 - 1]$328 = P$[441/400 -1]$328 = P$[{441 - 400}/400]$P = ${328 × 400}/41$ = Rs.3200S.I. = ${PRT}/100 = {3200 × 5 × 2}/100$ = Rs.320Using Rule 10,Here, C.I. = Rs.328, R = 5%, S.I. = ?C.I.= S.I.$(1 + R/200)$328 = S.I.$(1 + 5/200)$328 = S.I.$(1 + 1/40)$S.I. = ${328 × 40}/41$S.I. = 8 x 40 = Rs.320
Question 58. If the compound interest on a certain sum for 2 years at 3% per annum is Rs.101.50, then the simple interest on the same sum at the same rate and for the same time will be
  1.    Rs.98.25
  2.    Rs.90.00
  3.    Rs.100.00
  4.    Rs.95.50
 Discuss Question
Answer: Option C. -> Rs.100.00
Answer: (c)Let the sum be P.101.50 = P$[(1 + 3/100)^2 - 1]$[Since, C.I. = P$[(1 + r/100)^n - 1]$]101.50 = P$[(103/100)^2 - 1]$=P$({10609 - 10000}/10000)$P = Rs.${101.50 × 10000}/609 = Rs.1015000/609$S.I. = ${1015000 × 2 × 3}/{609 × 100}$ = Rs.100 Using Rule 10,The simple interest for a certain sum for 2 years at an annual rate interest R% is S.I., thenC.I. = S.I.$(1 + R/200)$
Question 59. The simple interest on a certain sum of money for 2 years at 5% is Rs.1600. The compound interest at the same rate after 3 years interest compound annually, is
  1.    Rs.2535
  2.    Rs.2520
  3.    Rs.2555
  4.    Rs.2522
 Discuss Question
Answer: Option D. -> Rs.2522
Answer: (d)Principal = $\text"S.I. × 100"/\text"Time × Rate"$= ${1600 × 100}/{5 × 2}$ = Rs.16000C.I. = P$[(1 + R/100)^T - 1]$= 16000$[(1 + 5/100)^3 –1]$= 16000$[(21/20)^3 - 1]$= $16000(9261/8000 - 1)$= ${16000 × 1261}/8000$ = Rs.2522
Question 60. There is 100% increase to an amount in 8 years, at simple interest. Find the compound interest of Rs.8000 after 2 years at the same rate of interest.
  1.    Rs.2125
  2.    Rs.2500
  3.    Rs.2250
  4.    Rs.2000
 Discuss Question
Answer: Option A. -> Rs.2125
Answer: (a)Using Rule 1,Let S.I. = Rs.100, & Principal = Rs.100Rate = $\text"S.I. × 100"/\text"Principal × Time"$= ${100 × 100}/{100 × 8} = 25/2$%C.I. = P$[(1 + r/100)^T - 1]$= 8000$[(1 + 25/200)^2 - 1]$= 8000 $(81/64 - 1)$= ${8000 × 17}/64$ = Rs.2125

Latest Videos
Chapter 1 - GLOBAL STEEL SCENARIO & INDIAN STEEL INDUSTRY Part 1 : (13-04-2024) INDUSTRY AND COMPANY AWARENESS (ICA)
Direction Sense Test Part 1 Reasoning (Hindi)
Chapter 1 - RMHP / OHP / OB & BP Part 1 : (14-02-2024) GPOE
Cube & Cuboid Part 1 Reasoning (Hindi)
Data Interpretation (DI) Basic Concept Reasoning (Hindi)
Counting Figures Part 1 Counting Of Straight Lines Reasoning (Hindi)
Sail E0 free webinar Webinars
Real Numbers Part 7 Class 10 Maths
Real Numbers Part 1 Class 10 Maths
Polynomials Part 1 Class 10 Maths

Latest Test Papers

DSP Combined 1 Free Revision Test SAIL JO E-0
GPOE / GPA Combined 1 Free Revision Test SAIL JO E-0
BSP Plant Specific Review Test SAIL JO E-0
BSL Combined 1 Free Revision Test SAIL JO E-0
GFM Combined 1 Free Revision Test SAIL JO E-0