Aptitude - Simple Interest - Discussion

Discussion Forum : Simple Interest - General Questions (Q.No. 1)

Simple Interest

A sum of money at simple interest amounts to Rs. 815 in 3 years and to Rs. 854 in 4 years. The sum is:

Rs. 650

Rs. 690

Rs. 698

Rs. 700

Answer: Option

Explanation:

S.I. for 1 year = Rs. (854 - 815) = Rs. 39.

S.I. for 3 years = Rs.(39 x 3) = Rs. 117.

Principal = Rs. (815 - 117) = Rs. 698.

Discussion:

174 comments Page 12 of 18.

Deepti said: 9 years ago

It is given in sum that SI of 3yrs is 815 so why we need to multiply 3 with 39 to get SI for 3 years?

Suraj.D said: 9 years ago

Please tell me if we subtract 854- 815 we get principal+ s.I for 1 year. Then can we consider it only s.I for 1 year? Please explain me.

Pradeep said: 9 years ago

Let 1 yr int .....x.
3yr int.......3x.
4yr int........4x.
(P+4x) - (P+3x) = 854 - 815,
x = 39.

Nirmala said: 9 years ago

Why we are not substructing 854? Please explain.

Manya said: 9 years ago

Thanks a lot @Gayatri.

Surjeet said: 9 years ago

Because we calculate with 3 years that is why we subtract from 815.

Anusha said: 9 years ago

Very helpful to understand the solution. Thanks for all your explanation.

Deepthy said: 9 years ago

Thanks @Pradeep.

Sunil said: 9 years ago

Thanks, I like this explanation.

This is helpful to understand the simple interest.

Pawan said: 9 years ago

How can we apply formula 100*SI/RT?

Here R is not given.

Post your comments here:

Quick links

Quantitative Aptitude

Verbal (English)

Reasoning

Programming

Interview

Placement Papers