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 4 of 10.
Kranti Kumar said:
8 years ago
Let me clear,
Rs 725 is not taken back. It is uniform through out the year.
Second thing --->
The rate of interest which is twice in case of 362.50.
Not for (725+ 362.50).
That's why it has taken twice rate of interest for 362.50.
Rs 725 is not taken back. It is uniform through out the year.
Second thing --->
The rate of interest which is twice in case of 362.50.
Not for (725+ 362.50).
That's why it has taken twice rate of interest for 362.50.
Himal said:
8 years ago
I think correct answer is 2.77...725 is only for 8 months/for the next four month a total of 725 + 362.5 is under consideration.
Ashu said:
8 years ago
S.I=725*r*2/3*100+362.50*2r+1/3*100=33.50.
Therefore,
1450R/300+750R/300=33.50,
= 4.83R+2.5R=33.50,
= 7.33R=33.50,
= R=33.50/7.33,
= R=4.5.
Therefore,
1450R/300+750R/300=33.50,
= 4.83R+2.5R=33.50,
= 7.33R=33.50,
= R=33.50/7.33,
= R=4.5.
Indramani said:
8 years ago
I didn't took that 4-month interest concept. suppose x is the interest per year, so per month, it will be x/12.
So then ((725*8*x) / (100*12)) + ((362.5*4*2x) / (100*12)) = 33.5.
Solving this gives x = 4.62.
So then ((725*8*x) / (100*12)) + ((362.5*4*2x) / (100*12)) = 33.5.
Solving this gives x = 4.62.
SEKHAR said:
4 years ago
Why don't we take it like this?
SI = (725 * 8 * R/100 * 2) + (362.50 * 4 * 2R/100 * 2).
SI = (725 * 8 * R/100 * 2) + (362.50 * 4 * 2R/100 * 2).
SHUBHaM SaKHaRE said:
7 years ago
725*(8/12)*r + (725+362.5)*(4/12)*2r = 33.5*100.
Hence;
r=2.77%.
Hence;
r=2.77%.
Anshul Gupta said:
7 years ago
Initially SI = 725 x R x 2
----------------- ( 8 months = 2/3 year)
3 x 100
= 4.83R.
After 8 months SI = (725+362.5) x 2R x 1.
-------------------------------(remaining 4 months = 1/3 year)
3 x 100.
= 7.25R.
According to Question:
33.5 = 4.83R + 7.25R
33.5 = 12.08R,
R = 33.5/12.08 = 2.77.
Is it right?
----------------- ( 8 months = 2/3 year)
3 x 100
= 4.83R.
After 8 months SI = (725+362.5) x 2R x 1.
-------------------------------(remaining 4 months = 1/3 year)
3 x 100.
= 7.25R.
According to Question:
33.5 = 4.83R + 7.25R
33.5 = 12.08R,
R = 33.5/12.08 = 2.77.
Is it right?
S.Padma said:
7 years ago
Principle=725 r=r% at the beginning of the year so t =1year.
After the 8 months sum of rupees, 362.50 is given additional so the total principle is P=725+362.50=1087.50
t =(12-8)=4 months i.e 4/12 so t=1/3 r=2r.
Rate =(725 * r * 1)/100 + ( 1087.50 * 2r * 1)/100*3 = 33.50
=> 725r +2175r = 33.50 * 100 *3.
=> 2900 r =10050,
=> r=10050/2900,
=> r=3.46%.
After the 8 months sum of rupees, 362.50 is given additional so the total principle is P=725+362.50=1087.50
t =(12-8)=4 months i.e 4/12 so t=1/3 r=2r.
Rate =(725 * r * 1)/100 + ( 1087.50 * 2r * 1)/100*3 = 33.50
=> 725r +2175r = 33.50 * 100 *3.
=> 2900 r =10050,
=> r=10050/2900,
=> r=3.46%.
Shibat said:
7 years ago
@S Padma.
Principle=725 r=r% at the beginning of the year so t =1year.
After the 8 months sum of rupees, 362.50 is given additional so the total principle is; P=725+362.50=1087.50,
t =(12-8)=4 months i.e 4/12 so t=1/3 r=2r.
Rate =(725 * r * 1)/100 + ( 1087.50 * 2r * 1)/100*3 = 33.50.
=> 725*3r +2175r = 33.50 * 100 *3.
=> 43500 r =10050,
=> r=10050/4350,
=> r=2.31.
Principle=725 r=r% at the beginning of the year so t =1year.
After the 8 months sum of rupees, 362.50 is given additional so the total principle is; P=725+362.50=1087.50,
t =(12-8)=4 months i.e 4/12 so t=1/3 r=2r.
Rate =(725 * r * 1)/100 + ( 1087.50 * 2r * 1)/100*3 = 33.50.
=> 725*3r +2175r = 33.50 * 100 *3.
=> 43500 r =10050,
=> r=10050/4350,
=> r=2.31.
Shibat sunwar said:
7 years ago
The Ans is 2.31.
Second principle is 725+362.5.
Second principle is 725+362.5.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers