Aptitude - Compound Interest - Discussion

Discussion Forum : Compound Interest - General Questions (Q.No. 7)
7.
At what rate of compound interest per annum will a sum of Rs. 1200 become Rs. 1348.32 in 2 years?
6%
6.5%
7%
7.5%
Answer: Option
Explanation:

Let the rate be R% p.a.

Then, 1200 x 1 + R 2 = 1348.32
100

1 + R 2 = 134832 = 11236
100 120000 10000

1 + R 2 = 106 2
100 100

1 + R = 106
100 100

R = 6%

Discussion:
41 comments Page 1 of 5.

Harika said:   1 decade ago
To find cp=p(1+R/100)^n-p but only amount is taken

Jasika said:   1 decade ago
1348.32 is CI, but here they have taken. Directly at the place of amount. ?

Vinoth said:   1 decade ago
Divide numerator and denominater by 100 to take out point. Tahts why 1200 as 120000.

Pawan said:   1 decade ago
Shakti borrows an amount of Rs 28000 for 2 years from a bank at a subsidised rate. At the end of 2 years he pays a sum of Rs 30870. How much was the rate of interest? What is the amount that should be paid if Shakti pays it after 3 years?

Solve it please?

G NARESH said:   1 decade ago
How you got 11236/10000?

Pinky said:   1 decade ago
By dividing numerator and denominator by 12 we got 11236/10000.

Praveen said:   1 decade ago
Let subtract sum from total amount 1348.32 - 1200 is 148.32.

148.32 is two years interest amt (profit) we get. Ten one year interest amount is 148.30/2 = 74 per annum.

Lets find the 74 amount interest rate of 1200 >>> 10% is 120 and then 6% is 74 Rs that all. 6% is right answer. Hope you understand this.

Rosy said:   1 decade ago
1348.32 = 1200(1+R/100)^2.

1.1236 = (1+R/100)^2.

(1.1236)^(1/2) = (1+R/100).

Since, divided half both sides,

1.06 = (1+R/100).

r = 6%.

Mounica said:   1 decade ago
Can any one explain this?

1348.32 is CI, but here they have taken directly at the place of amount?

Vaibhav patil jadhv said:   1 decade ago
@Mounika.

They didn't said 1348.32 is the compound interest they asked at what rate of the compound interest per annum the sum becomes 1348.32 from 1200 i.e 1348.32 can be equated to amount.

C.I = amount-sum.
Amount=sum(1+r/100)^t as the interest is compounded yearly.

Good luck.


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