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 3 of 10.
Soham said:
4 years ago
P=725 (for 8 months)
rate = R%.
So interest will be;
( 725 * R * 2/3 ) / 100 = 1450R/300.
P=1087.5 (For next 4 months),
Rate = 2R%.
So interest will be;
(1087.5 * 2R * 1/3)/100 = 2175R/300.
So,
(1450R/300 ) + (2175R/ 300 ) = 33.50,
3625R = 10050,
R = 10050/3625.
R = 2.77.
Am I right?
rate = R%.
So interest will be;
( 725 * R * 2/3 ) / 100 = 1450R/300.
P=1087.5 (For next 4 months),
Rate = 2R%.
So interest will be;
(1087.5 * 2R * 1/3)/100 = 2175R/300.
So,
(1450R/300 ) + (2175R/ 300 ) = 33.50,
3625R = 10050,
R = 10050/3625.
R = 2.77.
Am I right?
(6)
Dorji Tshering said:
4 years ago
Hello @Ugyen Dema,
We know S.I = P * R * T.
(725 * R * 1/100) + (362.50*2R*1/100*3)=33.50.
725R/100 + 725R/100*3 = 33.50.
After making same denominator we get,
(2175R/300)+ (725R/300)= 33.50,
(2175R+725R/300)= 33.50,
2900R= 33.50 * 300.
R= 10050/2900.
There by, R= 3.46.
We know S.I = P * R * T.
(725 * R * 1/100) + (362.50*2R*1/100*3)=33.50.
725R/100 + 725R/100*3 = 33.50.
After making same denominator we get,
(2175R/300)+ (725R/300)= 33.50,
(2175R+725R/300)= 33.50,
2900R= 33.50 * 300.
R= 10050/2900.
There by, R= 3.46.
(2)
Raj said:
7 years ago
Either this solution is wrong or question statements are misleading.
1. It says after 8 months, 362.50 MORE is lent so it seems it will become 725+362.50.
2. And total interest is of a year then first interest should be on first 8 months and next interest of 4 months?
1. It says after 8 months, 362.50 MORE is lent so it seems it will become 725+362.50.
2. And total interest is of a year then first interest should be on first 8 months and next interest of 4 months?
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.
Nias said:
3 years ago
After 8 months means he is lent for the remaining 4 months within the year. In a simple way, someone can't lend for the previous time rather he lent for the future time.
Therefore, the result of 1/4 we can understand from this concept.
Therefore, the result of 1/4 we can understand from this concept.
(7)
Tarun said:
1 decade ago
In question,just after 8 month,,principal change..725 only for 8 month..so its SI should b claculated only for 8 month and thn..for next 4 month the toatal amount(725+362.50) sholud consider as next 4 month principal..at rate 2R..
Shubhra said:
1 decade ago
(725 x R x 1 /100) + (362.50 x 2R x 1 /100 x 3 ) = 33.50
(725 x 1 /100 + 362.50 x 2 /100 x 3) R = 33.50
(725 x 3 + 725 / 100 x 3) R = 33.50
(2175 + 725 ) R = 33.50 x 100 x 3
(2900) R = 10050
R = 10050/2900
R = 3.46%
(725 x 1 /100 + 362.50 x 2 /100 x 3) R = 33.50
(725 x 3 + 725 / 100 x 3) R = 33.50
(2175 + 725 ) R = 33.50 x 100 x 3
(2900) R = 10050
R = 10050/2900
R = 3.46%
SIDDHARTH said:
4 years ago
@SOHAM.
NO, we should not take 2/3(YEAR) i.e 8 MONTHS.
BECAUSE the one who have borrowed the money have returned the money only after a year not in the middle i.e is 8 months so we considered it as a year and not as 2/3.
NO, we should not take 2/3(YEAR) i.e 8 MONTHS.
BECAUSE the one who have borrowed the money have returned the money only after a year not in the middle i.e is 8 months so we considered it as a year and not as 2/3.
(6)
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.
Venu said:
1 decade ago
Hey guys its correct.
Here 725 is given to the person for 1 year. Now you calculate the SI for that, later after 8 months, he again burrows again but the catch is rate is doubled.
Now you know :).
Here 725 is given to the person for 1 year. Now you calculate the SI for that, later after 8 months, he again burrows again but the catch is rate is doubled.
Now you know :).
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