Question

gopi invests rs 2500 for 5yrs. he also invests rs3500 for 3 years at the rate of 3% higher than the first rate.the total simple interest he earns from these togethrt is rs rs2155. find the two rates of interest

Answer 1

Let the rate of interest be x (for first case)
(for second case) the rate of interest = x+3

Now,
Si for case 1 =
$\frac{2500 \times 5 \times x}{100 } = 125x$
Si for case 2=
$\frac{3500 \times 3 \times (x + 3)}{100} = \frac{10500(x + 3)}{100} = 105x + 315$
As per question,

SI 1 + SI 2 =2155
SO,

125x + 105x + 315 = 2155
230x = 2155 - 315 = 1840
X =
$\frac{1840}{230} = 8$
So,
X= 8%

Therefore,
Rate of interest in case 1 = 8%
Rate of interest in case 2 = 8 + 3 = 11%

Hope this will be helping you

WARM REGARDS
Sahil khirwal

Answer 2

Answer:

Let the rate of interest be x (for first case)

(for second case) the rate of interest = x+3

Now,

Si for case 1 =

\frac{2500 \times 5 \times x}{100 } = 125x

100

2500×5×x

=125x

Si for case 2=

\frac{3500 \times 3 \times (x + 3)}{100} = \frac{10500(x + 3)}{100} = 105x + 315

100

3500×3×(x+3)

=

100

10500(x+3)

=105x+315

As per question,

SI 1 + SI 2 =2155

SO,

125x + 105x + 315 = 2155

230x = 2155 - 315 = 1840

X =

\frac{1840}{230} = 8

230

1840

=8

So,

X= 8%

Therefore,

Rate of interest in case 1 = 8%

Rate of interest in case 2 = 8 + 3 = 11%

Hope this will be helping you

warm regards Bhumi Rai