Question

Simple Interest for
sum of Rs.1230 for
2yr is Rs.10 more
than the simple
interest for Rs.1130
for same
duration. Find the
rate of Interest?
(a)5 (b)6 (c)8 (d)2
(e)​

Answer 1

Answer:

Rate of Interest = 5%

Step-by-step explanation:

According to the question,  

1230×2×R100−1130×2×R100=10  

R=100/20  

R=5%

Answer 2

Answer:

• Rate of interest is 5% per annum.

Step-by-step explanation:

Given that:

• Simple Interest for sum of ₹1230 for 2 years is ₹10 more than the simple interest for ₹1130 for same duration.

To Find:

• The rate of interest.

Let us assume:

• Rate of interest is x.

Then,

Simple Interest on ₹1230 for 2 years:

$\sf{SI=\dfrac{P\times R\times T}{100}}$

Substituting the values,

$\rm{\longmapsto\dfrac{1230\times x\times 2}{100}}$

Cutting off the zeros,

$\rm{\longmapsto\dfrac{123\!\!\!\not{0}\times x\times 2}{10\!\!\!\not{0}}}$

$\rm{\longmapsto\dfrac{123\times x\times 2}{10}}$

Reducing the numbers,

$\rm{\longmapsto\dfrac{123\times x\times 1}{5}}$

Multiplying the numbers,

$\rm{\longmapsto\dfrac{123x}{5}}$

Hence, simple interest is 123x/5.

Simple Interest on ₹1130 for 2 years:

$\sf{SI=\dfrac{P\times R\times T}{100}}$

Substituting the values,

$\rm{\longmapsto\dfrac{1130\times x\times 2}{100}}$

Cutting off the zeros,

$\rm{\longmapsto\dfrac{113\!\!\!\not{0}\times x\times 2}{10\!\!\!\not{0}}}$

$\rm{\longmapsto\dfrac{113\times x\times 2}{10}}$

Reducing the numbers,

$\rm{\longmapsto\dfrac{113\times x\times 1}{5}}$

Multiplying the numbers,

$\rm{\longmapsto\dfrac{113x}{5}}$

Hence, simple interest is 113x/5.

According to the question:

$\sf{\longmapsto\dfrac{123x}{5}-\dfrac{113x}{5}=10}$

Subtracting the numbers,

$\sf{\longmapsto\dfrac{123x-113x}{5}=10}$

$\sf{\longmapsto\dfrac{10x}{5}=10}$

Transposing 5 from LHS to RHS and changing its sign,

$\sf{\longmapsto10x=10\times5}$

Multiplying the numbers,

$\sf{\longmapsto10x=50}$

Transposing 10 from LHS to RHS and changing its sign,

$\sf{\longmapsto x=\dfrac{50}{10}}$

Dividing the numbers,

$\sf{\longmapsto x=5}$

Hence,

• x = 5

Therefore,

• Required rate of interest is 5% per annum.