Question

At what rate of simple interest will rupies 350 amount to rupees 455 in 6 year?

Answer 1

SI = P×T×R/100
SI=455
P=350
455= 350×6×R/100
455=21r
455÷21=r
22.75=r
22.75÷455×100
5%

Answer 2

Given: Amount (A)= 455 rupees

Time (T) = 6 years

Interest (I) = 350 rupees.

To find: Rate

Solution:  We know that Amount is the sum of interest and principal.

thus

$A=P+I$

$455=350+I\\I=455-350\\I=105....(i)$

and

Simple interest

$I=\frac{PRT}{100}$

$I=\frac{350\times R \times\ 6}{100}$

Substitute the value of $I$ from (i)

we get

$I=\frac{350\times R \times\ 6}{100}\\\\105=\frac{350\times R \times\ 6}{100}\\\\R=\frac{105\times 100}{350\times 6}\\\\R=5$

hence, the rate of interest is $5$ percent.