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 2 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
How comes after 8 months = 1/3 months?
I think 12 - 8 = 4, so we have to calculate the interest amount of the second amount for 1/4months.
I think 12 - 8 = 4, so we have to calculate the interest amount of the second amount for 1/4months.
(4)
Akram said:
2 years ago
Why 2R/3 is coming in the second S.I formula, it should be 1/3 only,right?
(3)
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)
Ajay said:
7 years ago
(725*R*8/12)/100 + (725+362.5*2R*4/12)100 = 33.5,
(725*R*8/12)/100 + (1087.5*2R*4/12)/100 = 33.5,
(483.33 R)/100 + (725 R)/100 = 33.50,
(483.33 R) + (725 R) = 33.5*100,
1208.33 R = 3350,
R = 3350/1208.33,
R = 2.772.
(725*2.772*8/12)/100 = 13.398.
(1087.5*5.544*4/12)/100 = 20.097.
By adding, we get 33.495.
(725*R*8/12)/100 + (1087.5*2R*4/12)/100 = 33.5,
(483.33 R)/100 + (725 R)/100 = 33.50,
(483.33 R) + (725 R) = 33.5*100,
1208.33 R = 3350,
R = 3350/1208.33,
R = 2.772.
(725*2.772*8/12)/100 = 13.398.
(1087.5*5.544*4/12)/100 = 20.097.
By adding, we get 33.495.
(2)
Sujeet said:
8 years ago
How, 2175 has come?
(1)
Rajnish said:
8 years ago
I didn't understand this problem, so please solve this problem simply.
(1)
Prakash c said:
2 years ago
1st amount of 725 is considered as 1 year amount then 2nd part of the amount is considered as 4 months interest. Then we will give the perfect answer.
(1)
Ugyen dema said:
4 years ago
How 2175 * 725? Please explain this.
(1)
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?
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