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 |
|
||||||||||||||||
|
|||||||||||||||||
|
|||||||||||||||||
|
|||||||||||||||||
| = Rs. 3321. |
C.I. = Rs. (3321 - 3200) = Rs. 121
Discussion:
220 comments Page 14 of 22.
ANUPAM DAS said:
9 years ago
1600 * 5/200 = 40(1st half)
1600 + 1600 + 40 = 3240
3240 * 5/200 = 81(2nd half )
So, total interest = 40 + 81 = 121.
1600 + 1600 + 40 = 3240
3240 * 5/200 = 81(2nd half )
So, total interest = 40 + 81 = 121.
Lithin Gowda said:
9 years ago
Thank you for all your answers.
Revant Borawat said:
9 years ago
Annually rate 5%.
for 1st installment 2.5 * 2.5 + 0.625 = 5.0625.
Amount=1681.
For 2nd 40 ÷ 1600 * 41 = 1640,
3321 - 3200 = 121.
for 1st installment 2.5 * 2.5 + 0.625 = 5.0625.
Amount=1681.
For 2nd 40 ÷ 1600 * 41 = 1640,
3321 - 3200 = 121.
S Simadri said:
9 years ago
Easy trick : compounded half yrly so 5%\2 = 2.5%.
1st half year interest : 2.5 % of 1600 = 40.
2nd half year intrest : 2.5% of 3200 + 2.5% of 40 = 81. Then CI is 40 + 81 = 121.
1st half year interest : 2.5 % of 1600 = 40.
2nd half year intrest : 2.5% of 3200 + 2.5% of 40 = 81. Then CI is 40 + 81 = 121.
Maneesh said:
9 years ago
Guys we are dealing here with the condition : When interest is compounded Half-yearly having formula.
Amount = P[1+(R/2)/100]^2n .
So in 1st case we have n=1 which means time is 1 year and in 2nd case, we have n=1/2 which mean half a year, simply put these values of 'n' and u will get the desired result.
Amount = P[1+(R/2)/100]^2n .
So in 1st case we have n=1 which means time is 1 year and in 2nd case, we have n=1/2 which mean half a year, simply put these values of 'n' and u will get the desired result.
Brijesh said:
9 years ago
1:- 6 month 1600 * 5 * 1/2 * 100 = 40.
2:- 6 month 1640 + 1600 = 3240.
3240 * 5 * 1/2 * 100 = 81.
Total:-3321 - 3200 = 121.
2:- 6 month 1640 + 1600 = 3240.
3240 * 5 * 1/2 * 100 = 81.
Total:-3321 - 3200 = 121.
Harshit said:
9 years ago
I am not able to get why the second term has the rate of interest as 5/2 but time is one year as we can see the second term has power 1.
Please clarify this.
Please clarify this.
S. GANESH BABU said:
8 years ago
Very smart explanation, thanks @Brijesh.
Asif Ansari said:
8 years ago
@ALL.
You all are facing problem because you are obsessed with "n" to substitute as "year" always.
"n" is basically how many "times" rate is applied on amount.
Here, it is clearly given that the interest is calculated on "half-yearly" basis. Now because of half yearly basis.
Here "n" will be "1" for 6 months (and r=r/2).
and "n" will be "2" for 1 year ( and r=r/2).
Suppose if it was given quarter-yearly,
"n" would be "1" for 3 months ( and r=r/4).
"n" would be "2" for 6 months (and r=r/4).
"n" would be "3" for 9 months (and r=r/4).
"n" would be "4" for 1 year (and r=r/4).
So, this guy kept his first 1600Rs amount for " two period" time.
that is, from 1st jan to 30th June (1st period) and from 1st July to 31st Dec (2nd Period).
he also deposited another amount on 1st July, this amount is kept for "one period".
That is, from 1st July to 31st Dec.
Therefore there is square(n=2) in a first Formula and no square(n=1) in a second formula.
Hope I helped little bit.
You all are facing problem because you are obsessed with "n" to substitute as "year" always.
"n" is basically how many "times" rate is applied on amount.
Here, it is clearly given that the interest is calculated on "half-yearly" basis. Now because of half yearly basis.
Here "n" will be "1" for 6 months (and r=r/2).
and "n" will be "2" for 1 year ( and r=r/2).
Suppose if it was given quarter-yearly,
"n" would be "1" for 3 months ( and r=r/4).
"n" would be "2" for 6 months (and r=r/4).
"n" would be "3" for 9 months (and r=r/4).
"n" would be "4" for 1 year (and r=r/4).
So, this guy kept his first 1600Rs amount for " two period" time.
that is, from 1st jan to 30th June (1st period) and from 1st July to 31st Dec (2nd Period).
he also deposited another amount on 1st July, this amount is kept for "one period".
That is, from 1st July to 31st Dec.
Therefore there is square(n=2) in a first Formula and no square(n=1) in a second formula.
Hope I helped little bit.
(1)
Rana suresh varma said:
8 years ago
1st calculate CI on 1600 half yearly for one year so 1600(1+5÷200)^2.
= 1600(205÷200)(205÷200),
= 1681,
= CI = 1681-1600 = 81->eqn1.
Next calculate CI on 1600 which is deposited after 6 months i.e. for 6 months.
= 1600(1+5÷200),
= 1600(205÷200),
= 1640.
= CI is = 1640-1600= 40->eqn2.
Add eqn1 and eqn2 we get;
= 81 + 40 = 121 this is the gain.
= 1600(205÷200)(205÷200),
= 1681,
= CI = 1681-1600 = 81->eqn1.
Next calculate CI on 1600 which is deposited after 6 months i.e. for 6 months.
= 1600(1+5÷200),
= 1600(205÷200),
= 1640.
= CI is = 1640-1600= 40->eqn2.
Add eqn1 and eqn2 we get;
= 81 + 40 = 121 this is the gain.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers