Aptitude - Compound Interest - Discussion
Discussion Forum : Compound Interest - General Questions (Q.No. 1)
1.
A bank offers 5% compound interest calculated on half-yearly basis. A customer deposits Rs. 1600 each on 1st January and 1st July of a year. At the end of the year, the amount he would have gained by way of interest is:
Answer: Option
Explanation:
| Amount |
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| = Rs. 3321. |
C.I. = Rs. (3321 - 3200) = Rs. 121
Discussion:
220 comments Page 5 of 22.
Amit said:
6 years ago
raman has some amount which he invests in two different banks.the rate of interest in first bank is 10% is compounded yearly while the rate of interest in second bank is 15% compounded yearly .if he gets equal amount of interest after 2 years from both banks then the deposit in first bank is what percent of total original amount?
Santhosh said:
5 years ago
First of all, we need to understand that first amount of 1600 for 1 year it is compounded half-yearly that means taking half of the interest for 2 years, and another amount is the only half year that is take half of the interest for one year, so finally, the total interest is; 5.0625 + 2.5 = 7.5625%.
So, 7.5625% of 1600 = 121.
So, 7.5625% of 1600 = 121.
Siva nandi reddy said:
1 decade ago
There is no formula to get the answer.
Simple logic is there that,
For 1 year 80/- is the interest then half of that amt is 40/- for half year.
So next half year for Jan amount 40/- and 1/- (it is obtained on first half interest). So total is 81/-.
and for July amt 40 because it is also half year, So the total is 121/-.
Simple logic is there that,
For 1 year 80/- is the interest then half of that amt is 40/- for half year.
So next half year for Jan amount 40/- and 1/- (it is obtained on first half interest). So total is 81/-.
and for July amt 40 because it is also half year, So the total is 121/-.
KAJAL said:
9 years ago
I solve this by the simple interest method.
Where p = 1600, r = 5, T = 0.5(6 months) (January amount).
Interest = (1600*5*0.5)/(100*2) = 40 Rs.
Now p =1640(January) + 1600(newly added in July).
So, p = 3240, r = 5, t = 0.5(6 months).
Interest = (3240*5*0.5)/(100*2) = 81 Rs.
Now the total interest = 40 Rs + 81 Rs =121 Rs.
Where p = 1600, r = 5, T = 0.5(6 months) (January amount).
Interest = (1600*5*0.5)/(100*2) = 40 Rs.
Now p =1640(January) + 1600(newly added in July).
So, p = 3240, r = 5, t = 0.5(6 months).
Interest = (3240*5*0.5)/(100*2) = 81 Rs.
Now the total interest = 40 Rs + 81 Rs =121 Rs.
Ashok raj said:
7 years ago
@All.
An interest usually is given year base so here calculated compounded half yearly that's why to split interest in two parts first 2.5 on 1600 is 40 and after 6 months he invested again 1600 total 3200 so 2.5 on 3200 is 80 and comp interest means interest on previous year 2.5 on 40 is 1 total interest is 40+80+1=121.
An interest usually is given year base so here calculated compounded half yearly that's why to split interest in two parts first 2.5 on 1600 is 40 and after 6 months he invested again 1600 total 3200 so 2.5 on 3200 is 80 and comp interest means interest on previous year 2.5 on 40 is 1 total interest is 40+80+1=121.
Shubham Torkad said:
5 years ago
@ALL.
An explanation for why there is square in 1 st term in amount.
As there is square in first term amount indicating the duration because the CI given here is the half-yearly basis not yearly so from,
1 st Jan -1st Jan(next year)=1 year =2 half year.n=2
1st Jul- 1st Jul(next year)=6 months=1 half-year ie.n=1
An explanation for why there is square in 1 st term in amount.
As there is square in first term amount indicating the duration because the CI given here is the half-yearly basis not yearly so from,
1 st Jan -1st Jan(next year)=1 year =2 half year.n=2
1st Jul- 1st Jul(next year)=6 months=1 half-year ie.n=1
Kurdush said:
4 years ago
Amount after 1 year on Rs 1600 (deposited on 1st. Jan)
= 1600(1+5/2100)^(2*1)=1600(41/40)^2,
= 1681.
Compound interest
= 1681 - 1600
= 81.
Amount after 12 year on Rs 1600(deposited on 1st Jul)
= 1600(1+5/2100)^(2*(1/2))
= 1600(41/40)
= 1640
Compound interest
=1640 - 1600 = 40.
Required gain;
= 81 + 40,
= 121.
= 1600(1+5/2100)^(2*1)=1600(41/40)^2,
= 1681.
Compound interest
= 1681 - 1600
= 81.
Amount after 12 year on Rs 1600(deposited on 1st Jul)
= 1600(1+5/2100)^(2*(1/2))
= 1600(41/40)
= 1640
Compound interest
=1640 - 1600 = 40.
Required gain;
= 81 + 40,
= 121.
(5)
Amit said:
1 decade ago
CI is nothing but interest on interest.
so first find SI for 1600
so SI= (1600 * 5 * 1/2)/100 = 40
now total money is 1640 after 6 month. he again deposit 1600 rs so
now in july beginning total money is 1640 + 1600 = 3240 rs
again find SI = (3240 * 5 * 1/2)/100 = 81 rs
So total interest is = 81 +40 = 121 Rs ans.
so first find SI for 1600
so SI= (1600 * 5 * 1/2)/100 = 40
now total money is 1640 after 6 month. he again deposit 1600 rs so
now in july beginning total money is 1640 + 1600 = 3240 rs
again find SI = (3240 * 5 * 1/2)/100 = 81 rs
So total interest is = 81 +40 = 121 Rs ans.
Mrudhula said:
1 decade ago
Let me explain in my point of view...
Firstly... i have calculated the compound interest of 1600/- for 1year..i.e,
[1600*[1+(5/100)]]=80
Then at 7th month the total amount=3200/-
So the compound interest of 3200 for (1/2)year is..
[3200*[1+(5/200)]^2]=162
Now the average of 80 and 162 is..
(80+162)/2 = 121
Firstly... i have calculated the compound interest of 1600/- for 1year..i.e,
[1600*[1+(5/100)]]=80
Then at 7th month the total amount=3200/-
So the compound interest of 3200 for (1/2)year is..
[3200*[1+(5/200)]^2]=162
Now the average of 80 and 162 is..
(80+162)/2 = 121
Kasinath @Hyd said:
1 decade ago
Since Bank offers compound interest on HALF YEARLY basis: so convert 1 Year into two Half years. so, use only half year formula.
Half Year formula: (1+ R/2*100)^2n.
1 year = Half Year + Half Year.
=>(1+ R/2*100)^2*1 n=1 is bcoz (1/2 +1/2).
Half year = (1+ R/2*100)^1 1 is bcoz (2*1/2) here n=1/2.
Half Year formula: (1+ R/2*100)^2n.
1 year = Half Year + Half Year.
=>(1+ R/2*100)^2*1 n=1 is bcoz (1/2 +1/2).
Half year = (1+ R/2*100)^1 1 is bcoz (2*1/2) here n=1/2.
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