M4maths Previous Puzzles

23 Jul 2015 Compound Interest

The compound interest on a sum for 2 years is Rs. 832 and the simple interest on the same sum for the same period is Rs. 800. The difference between the compound interest and the simple interest for 3 years will be

OPtion

1) Rs. 48.35
2) Rs. 46.25
3) Rs. 86.50
4) Rs. 92.25
5) Rs. 97.65
6) Rs. 66.56
7) Rs. 68.25
8) Rs. 98.56
9) Rs. 96.48
10)None of these

Solution

SI for 1 years = Rs. 400
SI on Rs. 400 for 1 year = Rs.(832-800)
Rate = 32/400 * 100 = 8%
Difference for 3rd year = SI on Rs. 832
Rs. 832* 8/100 * 1 = 66.56
Total difference = Rs.(32+66.56) = Rs. 98.56
Option 8)

Correct Option: 8 Best Solution (15)

swarupa nuggu   9 years AGO

Given that simple interest for 2 years is Rs.800

i.e., Simple interest for 1st year is Rs.400
and simple interest for 2nd year is also Rs.400

Compound interest for 1st year will be 400
and Compound interest for 2nd year will be 832 - 400 = 432

you can see that compound interest for 2nd year is more than simple interest for 2nd year by 432 - 400 = Rs.32

i.e, Rs. 32 is the interest obtained for Rs.400 for 1 year

Rate, R = 100×SIPT =100×32400×1 =8%

Difference between compound and simple interest for the 3rd year
= Simple Interest obtained for Rs.832

=PRT100 =832×8×1100 =Rs. 66.56

Total difference between the compound and simple interest for 3 years
= 32 + 66.56 = Rs.98.56

Like? Yes (23) | No (5)  

vini   9 years AGO

Given SI = 800 for two years
The SI and CI for first year is same = Rs . 400
CI for second year is (832-400= 432) so, extra Rs 32 is interest for previous year SO, R% of 400 = 32
R= 8%
Principal = Rs 5000
Now, SI for three years is Rs 1200
CI for three years is Rs 1298.56
The difference is 98.56

Like? Yes (17) | No (5)  

Dhanraj Wanjare   9 years AGO

CI=832 n=2 years SI=800, T=2 years
CI = P(1+R/100)^n - P; AND SI = P*R*T/100;
832=P(1+R/100)^2 - P; 800=P*R*2/100;
832=P{[(100+R)^2/10000]-1} P=800*100/2R;
832*10000=P[(10000+R^2+2*100*R)-10000];
8320000=P[R^2 + 200R];
8320000/P=R^2 + 200R
8320000/(800*100/2R)=R^2+200R;
208R=R^2+200R;
8R=R^2;
R=8;

P=800*100/2R
P=800*100/2*8;
P=5000;

NOW n=T=3 YEARS R=8% P=5000

CI = P(1+R/100)^3 - P; AND SI=P*R*T/100;
CI = 5000(1+8/100)^3 -5000; SI=5000*8*3/100; CI = 500*108^3/100^3 - 5000; SI=1200;
CI = 1298.56;

RESULT = CI - SI;
RESULT = 1298.56 - 1200;
RESULT = 98.56;

OPTION 8 IS SATISFIED ;

Like? Yes (6) | No (1)  

praveendas   9 years AGO

let find the amount which gives 800 on smple intrest for 2 years and 832 on cmpnd intrest for 2 years is 5000...
therfore for three years on simple intrest it is 1200
and for compound it is 1298.56..
1298.56-1200=98.56

Like? Yes (7) | No (3)  

KUMAR HARSH   9 years AGO

difference in C.I and S.I in 2years =Rs.32
S.I for 1year =Rs.400
S.I for Rs.400 for one year =Rs.32
rate=[100*32)/(400*1)%=8%
difference between in C.I and S.I for 3rd year
=S.I on Rs.832= Rs.(832*8*1)/100=Rs.66.56
Total difference between the compound and simple interest for 3 years
= 32 + 66.56 = Rs.98.56

Like? Yes (5) | No (1)  

Anuj Rai   9 years AGO

Compound interest for 1st year will be 400
and Compound interest for 2nd year will be 832 - 400 = 432

you can see that compound interest for 2nd year is more than simple interest for 2nd year by 432 - 400 = Rs.32

i.e, Rs. 32 is the interest obtained for Rs.400 for 1 year

Rate, R = 100×SIPT=100×32400×1=8%

Difference between compound and simple interest for the 3rd year
= Simple Interest obtained for Rs.832

=PRT/100=832×8×1100=Rs. 66.56

Total difference between the compound and simple interest for 3 years
= 32 + 66.56 = Rs.98.56

Like? Yes (4) | No (1)  

Veerraj Chauhan   9 years AGO

Given that simple interest for 2 years is Rs.800

i.e., Simple interest for 1st year is Rs.400
and simple interest for 2nd year is also Rs.400

Compound interest for 1st year will be 400
and Compound interest for 2nd year will be 832 - 400 = 432

you can see that compound interest for 2nd year is more than simple interest for 2nd year by 432 - 400 = Rs.32

i.e, Rs. 32 is the interest obtained for Rs.400 for 1 year

Rate, R = 100×SIPT=100×32400×1=8%

Difference between compound and simple interest for the 3rd year
= Simple Interest obtained for Rs.832

=PRT100=832×8×1100=Rs. 66.56

Total difference between the compound and simple interest for 3 years
= 32 + 66.56 = Rs.98.56

Like? Yes (5) | No (2)  

sudiptaa   9 years AGO

SI for 1st year =400
SI for 2nd year=400

CI for 1st year = 400
CI for 2nd year = 832-400= 432

compound interest for 2nd year is more than simple interest for 2nd year by 432 - 400 = Rs.32

i.e, Rs. 32 is the interest obtained for Rs.400 for 1 year

Rate, R = 100*SI*P*T=100×32400×1=8%

Difference between compound and simple interest for the 3rd year
= Simple Interest obtained for Rs.832

=PRT/100=832×8×1100=Rs. 66.56

Total difference between the compound and simple interest for 3 years
= 32 + 66.56 = Rs.98.56

Like? Yes (5) | No (2)  

Chitra.S   9 years AGO

Given that simple interest for 2 years is Rs.800

i.e., Simple interest for 1st year is Rs.400
and simple interest for 2nd year is also Rs.400

Compound interest for 1st year will be 400
and Compound interest for 2nd year will be 832 - 400 = 432

you can see that compound interest for 2nd year is more than simple interest for 2nd year by 432 - 400 = Rs.32
i.e, Rs. 32 is the interest obtained for Rs.400 for 1 year



Difference between compound and simple interest for the 3rd year
= Simple Interest obtained for Rs.832



Total difference between the compound and simple interest for 3 years
= 32 + 66.56 = Rs.98.56

Like? Yes (3) | No (1)  

SHAKE MAHAMAD GOUSE   9 years AGO

difference in C.I and S.I in 2years =Rs.32
S.I for 1year =Rs.400
S.I for Rs.400 for one year =Rs.32
rate=[100*32)/(400*1)%=8%
difference between in C.I and S.I for 3rd year
=S.I on Rs.832= Rs.(832*8*1)/100=Rs.66.56
S.I for 3 years is Rs.1232=Rs.(1232*8*1)/100=Rs.98.56

Like? Yes (2) | No   

SURAJ NIRALA   9 years AGO

On applying the firmula of si and ci ,
two equation form where pr=40000.
putting tge value of pr in ci formula we fet r=8%
now on finding the intersts the difference is 98.56

Like? Yes (2) | No (1)  

Dinni   9 years AGO

Difference in C.I. and S.I. for 2 years = Rs. 32.

S.I. for one year = Rs. 400.

∴ S.I. on Rs. 400 for one year = Rs. 32.

So, Rate = 100∗32400∗1%=8%.

Hence, difference in C.I. and S.I. for 3rd year

= S.I. on Rs. 832 = Rs. (832∗8∗1100) = Rs. 66.56.

Total difference = Rs. (32 + 66.56) = Rs. 98.56.

Like? Yes (3) | No (2)  

anuj gupta   9 years AGO

Given that simple interest for 2 years is Rs.800

i.e., Simple interest for 1st year is Rs.400
and simple interest for 2nd year is also Rs.400

Compound interest for 1st year will be 400
and Compound interest for 2nd year will be 832 - 400 = 432

you can see that compound interest for 2nd year is more than simple interest for 2nd year by 432 - 400 = Rs.32

i.e, Rs. 32 is the interest obtained for Rs.400 for 1 year

Rate, R = 100×SIPT=100×32400×1=8%

Difference between compound and simple interest for the 3rd year
= Simple Interest obtained for Rs.832

=PRT100=832×8×1100=Rs. 66.56

Total difference between the compound and simple interest for 3 years
= 32 + 66.56 = Rs.98.56

Like? Yes (1) | No   

Riyashree Mukherjee   9 years AGO

diff of ci &si for 2 years =32
find for another one yr and then add

Like? Yes (1) | No (1)  

GITANJALI GOSWAMI   9 years AGO

diff of ci and si=32
si of 1 year=400
rate=8%
diff of ci and si on third year=si on rs.832=66.56
total diff=(32+66.56)=98.56

Like? Yes (2) | No (2)