Aptitude - Simple Interest - Discussion
Discussion Forum : Simple Interest - General Questions (Q.No. 9)
9.
A sum of Rs. 725 is lent in the beginning of a year at a certain rate of interest. After 8 months, a sum of Rs. 362.50 more is lent but at the rate twice the former. At the end of the year, Rs. 33.50 is earned as interest from both the loans. What was the original rate of interest?
Answer: Option
Explanation:
Let the original rate be R%. Then, new rate = (2R)%.
Note:
Here, original rate is for 1 year(s); the new rate is for only 4 months i.e. 
year(s).
 |
 |
725 x R x 1 |  |
+ | |
362.50 x 2R x 1 | |
= 33.50 |
| 100 | 100 x 3 |
(2175 + 725) R = 33.50 x 100 x 3
(2175 + 725) R = 10050
(2900)R = 10050
| R = |
10050 | = 3.46 |
| 2900 |
Original rate = 3.46%
Discussion:
97 comments Page 7 of 10.
Mani said:
1 decade ago
after 8 months principle should be 725+362.50 but in answer he was write only 362.50 how will it come?
And original rate only 8 months so time=8/12 years but he was write 1 year. how is?
And original rate only 8 months so time=8/12 years but he was write 1 year. how is?
Amith sourya said:
1 decade ago
The solution he given is wrong. Because for first case he took 8 months and for second month he took the remaining months i.e. 12-8 = 4. But he took in solution as 1 year.
Sudhanshu said:
1 decade ago
In the question the SI for the second loan should be calculated for 4 months and not the whole year.
Vijay said:
1 decade ago
Hi,
In this question,for 8 months 750 with r%,remaining 362.5 with 2r% but he is doing for 1 year & 4 months,may be the answer is wrong ? what he explained.
In this question,for 8 months 750 with r%,remaining 362.5 with 2r% but he is doing for 1 year & 4 months,may be the answer is wrong ? what he explained.
Satnam said:
1 decade ago
Here, original rate is for 1 year (s) ; the new rate is for only 4 months i.e. 1/3year (s).
Can anybody explain this line. How it becomes 1/3 ?
Can anybody explain this line. How it becomes 1/3 ?
Mariam said:
1 decade ago
Suman answer is wrong. Because in question he lent the amt and doesnt paid it back. If he pays after 8 months we can consider it as 8/12. Explanation given to the answer is correct.
Shashi said:
1 decade ago
The interest of Rs725 he had collect at the end of the year with the interest of 4 months of Rs 362.5 so calculate it &you will get the correct answer.
Suman said:
1 decade ago
Let the original rate is r%, then new rate is 2r.
here original rate is for only 8 months i.e 2/3; new rate is for 4 month i.e 1/3year(s).
=>{(725*r*2)/(100*3)}+{(362.50*2r*1)/(100*3)}=33.50
=>4.8333333333r+2.4166666667r=33.50
=>7.25r=33.50
=>r=33.50/7.25
=>r=4.6206896552
i.e original rate=4.62%
here original rate is for only 8 months i.e 2/3; new rate is for 4 month i.e 1/3year(s).
=>{(725*r*2)/(100*3)}+{(362.50*2r*1)/(100*3)}=33.50
=>4.8333333333r+2.4166666667r=33.50
=>7.25r=33.50
=>r=33.50/7.25
=>r=4.6206896552
i.e original rate=4.62%
Supriya said:
1 decade ago
I think the correct solution is as follows:
1) consider P=725, R=r, n= 8 months
SI= [725*(8/12)*r]/100= 4.833r
Amount= SI+P
Amount= 4.833r+725
this amount will be principle for next step
2) P= (4.833r+725)+362.5 = 1087.5+4.833r
R= 2r, n=4 months
SI= [ (1087.5+4.883r)*(4/12)*2r]/100 = 33.5
solving this r= 4.529%
Is this solution correct....??
please suggest me..!!
1) consider P=725, R=r, n= 8 months
SI= [725*(8/12)*r]/100= 4.833r
Amount= SI+P
Amount= 4.833r+725
this amount will be principle for next step
2) P= (4.833r+725)+362.5 = 1087.5+4.833r
R= 2r, n=4 months
SI= [ (1087.5+4.883r)*(4/12)*2r]/100 = 33.5
solving this r= 4.529%
Is this solution correct....??
please suggest me..!!
Aakash said:
1 decade ago
After reading it carefully I got it Tarun.
The rate of interest which is twice in case of 362.50 is twice only for 362.50 and not for (725+ 362.50)/
Second thing ---> don't take this question as a single 1. See both the problems with different view.
Rs 725 is not taken back it is uniform through out the year.
Still any kind of queries are welcomed.
The rate of interest which is twice in case of 362.50 is twice only for 362.50 and not for (725+ 362.50)/
Second thing ---> don't take this question as a single 1. See both the problems with different view.
Rs 725 is not taken back it is uniform through out the year.
Still any kind of queries are welcomed.
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