Question

find the principal when time=4 years, simple intrest = rs 400 and rate of intrest = 5% p.a​

Answer 1

★ Concept

We are provided with the Simple Interest, Rate of Interest and Time period. We have to calculate the Principal. In order to find Principal we'll make use of the general formula for Simple Interest and from that we can make a subject formula for calculating Principal.

Let's proceed with Calculation !!

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Given

» Simple Interest = ₹ 400

» Rate of Interest = 5 %

» Time Period = 4 years

» Principal = ?

Formula for Simple Interest

Simple Interest = (Principal × Rate × Time)/ 100.

Forming a Subject Formula for the Calculation of Principal.

Principal = (Simple Interest × 100)/(Rate× Time)

$↠ \sf \: Principal = \dfrac{400 \times100 }{5 \times 4}$

$↠ \sf \: Principal = \dfrac{40000 }{20}$

$↠ \sf \: Principal = \bf ₹ \ 2000$

Therefore, ₹ 2000 is the required principal under the given circumstances.

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More to know

Here in the question we are asked to calculate Principal so we have applied the formula

Principal = (S.I. × 100)/(Rate× Time)

If we are provided with Principal and S.I. and asked to calculate either Rate of Interest and Time Period then

For Finding Rate

Rate = (S.I. × 100)/(Principal × Time)

Rate is expressed in terms of percentage(%).

For Finding Time Period

Time = (S.I. × 100)/(Principal × Rate)

Time is expressed in terms of years or might be in months depending upon the question.