C.I. and S.I. Quiz based on and Tricks

1. Mohan invested a certain sum in a simple interest bond whose value grew to Rs. 300 at the end of 3 yr and to Rs. 400 at the end of another 5 yr. The rate of interest was

(a) 12%

(b) 12.5%

(c) 8.33%

(d) 6.67%

2. Suman lent some money to Rohan at 6% p.a. simple interest. Rohan lent the entire amount to Mira on the same day at 8.5 % p.a. In this transaction Rohan earned a profit of Rs. 250. Find the sum lent by Suman to Rohan.

(a) Rs. 7500

(b) Rs. 12500

(c) Rs. 10000

(d) Rs. 8000

3. On retirement, a person gets 1.53 lakhs of his provident find which he invests in a scheme at 20% p.a. His monthly income from this scheme will be

(a) Rs. 2,450

(b) Rs. 2,500

(c) Rs. 2, 550

(d) Rs. 2,600

4.If Rs. 450 amount to Rs. 540 in 4 years, what will it amount to in 6 years at the same rate %?

(a) Rs. 600

(b) Rs. 585

(c) Rs. 700

(d) Rs. 640

5.In what time will Rs. 64,000 invested at 5% p.a. fetch an interest of Rs. 4,921, the interest being compounded half yearly.

(a) 2/3 years

(b) 4/5 years.

(c) 2 years

(d) 3/2 years

6.The population of a city two years ago was 1,25,000. Due to migration from cities, it decreases every year at the rate of 4% per annum. Find its present population. How many person have migrated in last two years?

(a) Rs. 7,500

(b) Rs. 9,800

(c) Rs. 5,600

(d) Rs. 2,600

7.The population of a town in the year 2001 was 4 lakhs. Due to migration from cities, it decreases every year at the rate of 40 per thousand. Find the population of the town in lakhs during 2003.

(a) 4.41

(b) 4.21

(c) 4.84

(d) 3.68

8.A sum of money at compound interest amounts to thrice itself in three years. In how many years will it be nine times itself?

(a) 18

(b) 12

(c) 6

(d) Data Insufficient

9.The difference between simple and compound interest on a certain sum of money for 3 years at 5 per cent per annum is Rs. 325. The sum of money is :

(1) Rs. 42623

(2) Rs. 46255

(3) Rs. 43260

(4) Rs. 35990

10.The difference between simple and compound interest on a certain sum of money for 2 years at 4 per cent per annum is Rs. 12. The sum of money is :

(1) Rs. 7600

(2) Rs. 7625

(3) Rs. 7500

(4) Rs. 7650

Answers and Solution:

1.(c)
(Pr*3)/100 +P = 300.......(1)
(Pr*8)/100 +P = 400.......(2)
subtract (1) from (2)
p*r = 2000 ...........(3)
put (3) in (1)
p = 240, then r = 8.33%

2.(c)
3.(c)
Use, SI = PRT/100 = (153000*20)/100*1/12 = Rs. 2550

4.(b)
SI per year = (540-450)/4 = 22.5
so after 6 year = 22.5 x 6 = 135
So Amount 450+135 = Rs.585

5.(d)
6.(b)
Population 2 year ago = 125000 = p
for two years,rate of decrease = 4% p.a.
population after 2 year = present population = p(1-R/100)^2
Present population = 125000(1-4/100)^2
= 115200
So number of persons migrated during last 2 years= 125000-115200 = 9800

7.(d)
8.(c)
9.(a)
Difference of CI and SI for 3 years = pr^2(300+r)/(100)^3
325 = (p*25*305)/1000000
so p = 42623

10.(3)
Difference of CI and SI for 2 years = pr^2/(100)^2
12 = (p*16)/10000
so p = 7500