Simple and Compound Interest

¼ lk/kkj.k vkSj pØo`f) C;kt ½

Chapter Rating: 1*
No. of questions asked in CSAT over the years ¼fiNys o"kksaZ esa lhlSV esa iwNs x, ç'uksa dh la[;k½

2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 Total

0 0 0 0 0 0 0 1 0 0 0 0 1 0 2

TYPE-1
P- Principal, R- Rate of interest
T- time period, SI- Simple Interest
P R  T SI  100
SI = ,P=
100 RT
SI  100 SI  100
R= ,T=
PT R P

Ex 1. What sum of money must be given as simple interest for six

months at 4% per annum in order to earn Rs. 150 as interest?
4% çfr o"kZ dh nj ls lk/kkj.k C;kt ds :i esa 150 C;kt #i;s
dekus ds fy, Ng eghus ds fy, fdruh jkf'k nh tkuh pkfg,\
(a) Rs. 5000 (b) Rs. 7500
(c) Rs. 10000 (d) Rs. 15000
Ex 2. The sum of money that will yield Rs. 60 as simple interest at
the rate of 6% per annum in 5 years is?
/ku dh jkf'k tks 5 o"kksZa esa 6% çfr o"kZ dh nj ls lk/kkj.k C;kt ds
:i esa 60 # gS\
(a) 200 (b) 225
(c) 175 (d) 300
Q1. In what time will Rs. 8000, at 3% per annum, produce the
same interest as Rs. 6000 does in 5 years at 4% simple
interest?
fdrus le; esa 8000 #] 3% çfr o"kZ ij] #i;s ds leku C;kt dk
mRiknu djrs gSa ftruh 6000 # 5 lky esa 4% lk/kkj.k C;kt ij
djrk gS\
(a) 5 years (b) 6 years
(c) 3 years (d) 4 years
Q2. The rate of simple interest for which Rs. 6000 will amount to
Rs. 6900 in 3 years is:-
lk/kkj.k C;kt dh nj ftlds fy, 6000 #i;s dh jkf'k 3 o"kksZa esa 6900
gksxh gS%
(a) 5% (b) 7%
(c) 2% (d) 4%
Q3. Reena took a loan of Rs.1200 with simple interest for as
many years as the rate of interest. If she paid Rs.432 as
interest at the end of the loan, what was the rate of interest?
jhuk us 1200 #i;s dk _.k lk/kkj.k C;kt ij mrus gh o"kksZa ds fy,
fy;k ftruh C;kt nj FkhA ;fn mlus _.k ds var esa C;kt ds :i esa
432 #i;s dk Hkqxrku fd;k] rks C;kt dh nj D;k Fkh\(MPSC 2018)
(a) 3.6 (b) 6
(c) 18 (d) 20

TYPE-2
Ex 3. If a sum of money at simple interest doubles in 12 years, the
rate of interest per annum is:-
;fn dksbZ /kujkf'k lk/kkj.k C;kt ij 12 o"kksZa esa nqxquh gks tkrh gS] rks
okf"kZd C;kt nj D;k gS\
2
(a) 16 % (b) 7.5%
3
1
(c) 8 % (d) 10%
3
1
Q4. In how many years will a sum of money double itself at 6 %
4
simple interest per annum?
1
6 % çfr o"kZ lk/kkj.k C;kt dh nj ls fdrus o"kksaZ esa dksbZ jkf'k
4
nqxuh gks tk,xh\
(a) 24 years (b) 20 years
(c) 16 years (d) 12 years
Q5. How many years will be required for an amount to be doubled
when the rate of simple interest is 5% per years?
tc lk/kkj.k C;kt dh nj 5% çfr o"kZ gS] rks fdlh jkf'k dks nksxquk
djus ds fy, fdrus o"kksZa dh vko';drk gksxh\(MPSC 2008)
(a) 5 (b) 10
(c) 15 (d) 20
TYPE-3
Ex 4. A sum of money lent out at simple interest amounts to Rs.
720 after 2 years and to Rs. 1020 after a further period of 5
years. The sum is:-
2 lky ckn lk/kkj.k C;kt ij m/kkj nh xbZ jkf'k #- 720, vkSj 5 lky
dh ,d vkSj vof/k ds ckn # 1020 gSA rks jkf'k D;k gS?
(a) Rs. 500 (b) Rs. 600
(c) Rs. 700 (d) Rs. 710

Q6. Rs. 500 was invested at 12% per annum simple interest and
a certain sum of money invested at 10% per annum simple
interest. If the sum of the interest on both the sums after 4
years is Rs. 480, the later sum of money is:-
#- 500 dks 12% çfr o"kZ lk/kkj.k C;kt ij fuos'k fd;k x;k Fkk vkSj
,d fuf'pr jkf'k 10% çfr o"kZ lk/kkj.k C;kt ij fuos'k dh xbZ FkhA
;fn 4 o"kksaZ ds ckn nksuksa jkf'k ij C;kt dh jkf'k #- 480 gS] ckn esa
fuos'k dh xbZ jkf'k D;k Fkh \
(a) Rs. 450 (b) Rs. 750
(c) Rs. 600 (d) Rs. 550
Q7. Mohan lent some amount of money at 9% simple interest and
an equal amount of money at 10% simple interest each for
two years. If his total interest was Rs. 760, what amount was
lent in each case?
eksgu us dqN jkf'k dks 9% lk/kkj.k C;kt ij vkSj mruh gh jkf'k dks
10% lk/kkj.k C;kt ij nks o"kksZa ds fy, m/kkj fn;kA ;fn mldk dqy
C;kt #- 760 gS] çR;sd ekeys esa fdruh jkf'k m/kkj nh xbZ Fkh\
(a) Rs. 1700 (b) Rs. 1800
(c) Rs. 1900 (d) Rs. 2000

TYPE- 4 COMPOUND INTEREST

n
 R 
C.I. = P  1 +  −P
 100 

Ex 5. Find the compound interest on 2000 Rs for 2 years at 10%

per annum compounded annually.
2000 #i;s ij 2 lky ds fy, 10% çfr o"kZ dh nj ls pØo`f) C;kt
Kkr dhft,A
Q8. Find compound interest on 50000 Rs for 2 years at 4% per
annum, compounding is done annually.
50000 #i;s ij 2 lky ds fy, 4% çfr o"kZ dh nj ls pØo`f) C;kt
Kkr dhft,] pØo`f) okf"kZd :i ls dh tkrh gSA
(a) Rs. 5000 (b) Rs. 4000
(c) Rs. 4080 (d) Rs. 4100

TYPE-5
Ex 6. The simple interest on a sum of money at 4% p.a. for 2 years
is Rs. 80. The compound interest on the same sum for the
same period is:-
fdlh /kujkf'k ij 4% çfr o"kZ dh nj ls 2 lky ds fy, lk/kkj.k
C;kt #- 80- gS A leku jkf'k ij leku vof/k ds fy, pØo`f) C;kt
gS\
(a) Rs. 82.60 (b) Rs. 82.20
(c) Rs. 81.80 (d) Rs. 81.60
1
Q9. If the compound interest on a sum for 2 years at 12 % per
2
annum is Rs.340, then the simple interest on the same sum
at the same rate for the same period of time is
1
;fn fdlh jkf'k ij 2 o"kZ ds fy, 12 % çfr o"kZ dh nj ls pØo`f)
2
C;kt 340 #i;s gS] rks mlh jkf'k ij leku vof/k ds fy, leku nj
ij lk/kkj.k C;kt D;k gS?
(UPPCS 2018)
(a) Rs.310 (b) Rs.320
(c) Rs.330 (d) Rs.350

TYPE-6
If the same amount P is invested at R% per annum
rate of interest under simple and compound interest
respectively for 2 years each. Then difference in
2
 R 
interests obtained is:- C.I. – S.I. = P  
 100 

Ex 7. The difference between the simple and compound interest on

a certain sum of money at 5% rate of interest per annum for 2
years is Rs. 15. Then the sum is?
,d fuf'pr jkf'k ij 5% çfr o"kZ dh nj ls 2 o"kZ ds fy, lk/kkj.k
vkSj pØo`f) C;kt ds chp dk varj #- 15- rks jkf'k D;k gS?
(a) Rs. 6500 (b) Rs. 5500
(c) Rs. 6000 (c) Rs. 7000
Q10. The difference between the compound interest (compounded
annually) and the simple interest on a sum of Rs. 1000 at a
certain rate of interest for 2 years is Rs. 10. The rate of
interest per annum is:-
2 lky ds fy, 1000 #i;s dh jkf'k ij pØo`f) C;kt ¼okf"kZd
pØo`f)½ vkSj lk/kkj.k C;kt ds chp dk varj 10 #i;s gSA çfro"kZ
C;kt dh nj D;k gS?
(a) 5% (b) 6%
(c) 10% (d) 12%
Q11. If the difference between S.I. and C.I. for 2 years on a sum of
money lent at 5% is Rs. 6, then the sum is:-
;fn S.I. vkSj C.I. ds chp dk varj 5% ij m/kkj nh xbZ jkf'k ij 2
o"kZ ds fy, #- 6 gS] rks jkf'k D;k gS?
(a) Rs. 2200 (b) Rs. 2400
(c) Rs. 2600 (d) Rs. 2000
Q12. The difference between the compound interest and simple
interest for 3 years at 5% per annum on Rs 8,000 will be?
8]000 #i;s ij 5% o"kZ dh nj ls 3 lky ds pØo`f) C;kt vkSj
lk/kkj.k C;kt ds chp dk varj D;k gS?
(UPPSC 2015)
(a) Rs 75 (b) Rs 69
(c) Rs 55 (d) Rs 61

TYPE-7
Ex 8. In order to buy a lift pump for his well, Sunil borrowed
Rs.16000 for 3 years at the rate of compound interest of
12.5% p.a. What would have been the difference in the
interest on this principal had he borrowed it at simple
interest?
vius dq,a ds fy, fy¶V iai [kjhnus ds fy,] lquhy us 12-5 çfr'kr
çfr o"kZ ds pØo`f) C;kt dh nj ls 3 lky ds fy, 16000 #i;s
m/kkj fy,A bl ewy/ku ij C;kt esa D;k varj gksrk ;fn og bls
lk/kkj.k C;kt ij m/kkj ysrk? (MPSC 2017)
(a) Ra.781.25 (b) Rs.718.50
(c) Rs.678.25 (d) Rs.687.25
Q13. A person bought a refrigerator worth Rs. 22,800 with 12.5%
interest compounded yearly. At the end of first year, he paid
Rs. 8,650 and at the end of second year Rs. 9,125. How
much will he have to pay at the end of third year to clear the
debt?
,d O;fä us 22]800 # dk jsfÝtjsVj lkykuk 12-5% C;kt ds lkFk
pØo`f) C;kt ds lkFk [kjhnkA çFke o"kZ ds var esa] mlus 8]650 #-
vkSj nwljs o"kZ ds var esa 9]125 #- Hkqxrku fd,A rhljs o"kZ ds var esa
mls dtZ pqdkus ds fy, fdruk Hkqxrku djuk gksxk\
(CSAT 2018)
(a) Rs. 9,990 (b) Rs. 10,000
(c) Rs. 10,590 (d) Rs. 11,250
Q14. A sum of Rs. 3000 amounts to Rs. 6000 in two years at
compound interest. The interest for four years is:
3000 #i;s dh jkf'k pØo`f) C;kt ij nks lky esa 6000 gks tkrh gSA
pkj lky ds fy, C;kt D;k gS?
(a) Rs. 11000 (b) Rs. 12000
(c) Rs. 6000 (d) Rs. 9000

TYPE-8
Ex 9. A sum of money doubles itself in 4 years at compound
interest. It will amount to 8 times itself at the same rate of
interest in how many years?
,d jkf'k pØo`f) C;kt ij 4 o"kksZa esa vius vki nqxuh gks tkrh gSA
;g jkf'k esa leku C;kt nj ij Lo;a dk 8 xquk gksus fy, fdrus o"kksZa
dh vko';drk gksxh\
(a) 18 years (b) 12 years
(c) 16 years (d) 24 years
Q15. A sum of money invested at compound interest doubles itself
in 6 years. At the same rate of interest, it will amount to eight
times of itself in how many years?
,d jkf'k pØo`f) C;kt 6 o"kksZa esa vius vki nqxuh gks tkrh gSA mlh
C;kt nj ij] fdrus o"kksZa esa ;g jkf'k Lo;a dk vkB xquk gks tk,xh ?
(a) 15 years (b) 12 years
(c) 18 years (d) 10 years
Q16. A certain sum of money in three years becomes thrice on
compound interest. In how many years it will be 9 times?
rhu o"kksZa esa ,d fuf'pr jkf'k pØo`f) C;kt ij rhu xquk gks tkrh gSA
fdrus o"kksaZ esa ;g 9 xquk gks tk,xk\
(UPPSC 2017)
(a) 6 years (b) 8 years
(c) 9 years (d) 12 years
Q17. A man’s investment doubles in every 5 years. If he invested
Rs.5000 in each of the years 1960, 1965, 1970, 1975, then
what was the total amount received by him in 1980.
,d vkneh dk fuos'k gj 5 lky esa nksxquk gks tkrk gSA ;fn mlus
çR;sd o"kZ 1960] 1965] 1970] 1975 esa ls çR;sd esa 5000 #i;s dk
fuos'k fd;k rks 1980 esa mls dqy fdruh jkf'k çkIr gqbZA
(UPSC IAS 1982)
(a) Rs.140000 (b) Rs.30000
(c) Rs.70000 (d) 150000