Question

3. The difference between simple interests received from two different banks on Rs 2000 for 2 years is Rs 30; the difference between their rates of interest is ______.​

Answer 1

Answer:

0.75%

Explanation:

Given that,

The difference between $\rm S_1$ and $\rm S_2$ recived from two banks on Rs.2,000 for 2 years is Rs.30

Find the difference between their rates of interest.

We know that,

$\rm \bullet \: \: S.I. = \dfrac{p \times r \times t}{100}$

Where,

• p(principal) = 2000
• t(time) = 2 years

So,

Calculating $\rm S_1 :—$

$\rm \therefore \: S_1 = \dfrac{2000 \times R \times 2}{100}$

$\rm = 40R$

And also,

$\rm \therefore S_2 = \dfrac{2000 \times r \times 2}{100}$

$\rm = 40r$

According to the question,

$\rm \implies \: S_1 - \rm S_2 = 30$

$\rm \implies \: 40R - 40r = 30$

$\rm \implies \: 40(R - r) = 30$

$\rm \implies \: (R - r) = \dfrac{30}{40}$

$\rm \implies \: (R - r) = \dfrac{3}{4}$

$\rm \therefore \: R - r = 0.75\%$

Required answer: 0.75%

__________________________

Note:

• $\rm S_1$ denotes the simple interest received from one bank.
• $\rm S_2$ denotes the simple interest received from another bank.

Answer 2

Answer:

0.75

Step-by-step explanation:

Principal (P) = ₹ 2000

Number of years (N) = 2 years

Rate of interest : Let R for first company and r for another company

$simple \: interest = \frac{pnr}{100}$

For first company,

$simple \: interest \: = \frac{2000 \times 2 \times R}{100} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 40R$

For second company,

$simple \: interest \: = \frac{2000 \times 2 \times r}{100} \\ \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: \: = 40r$

The difference between simple interests is ₹ 30.

.: 40R - 40r = 30

40 (R - r) = 30

$(R - r) = \frac{30}{40} = 0.75$

Hence, the difference between their rates of interest is 0.75 .