The simple interest on Rs 28,000 for four years is Rs 7,000, what is the rate per cent per annum?

Options

A. 0.05
B. `6 (1)/(4) %`
C. `10 % `
D. `12(1)/(2)`%

Answer

To find the rate of simple interest per annum, we can use the formula for simple interest:

\[ \text{Simple Interest (SI)} = \frac{P \times R \times T}{100} \]

Where:
- \( P \) = Principal amount (initial amount of money)
- \( R \) = Rate of interest per annum (in percentage)
- \( T \) = Time (in years)

Given:
- \( P = 28,000 \)
- \( T = 4 \) years
- \( SI = 7,000 \)

We need to find \( R \).

### Step 1: Substitute the known values into the formula

\[ 7,000 = \frac{28,000 \times R \times 4}{100} \]

### Step 2: Simplify the equation

Multiply both sides by 100 to eliminate the fraction:

\[ 7,000 \times 100 = 28,000 \times R \times 4 \]

\[ 700,000 = 112,000 \times R \]

### Step 3: Solve for \( R \)

Now, divide both sides by 112,000 to isolate \( R \):

\[ R = \frac{700,000}{112,000} \]

### Step 4: Simplify the fraction

To simplify, we can divide both the numerator and denominator by 28,000:

\[ R = \frac{700,000 \div 28,000}{112,000 \div 28,000} = \frac{25}{4} \]

### Step 5: Convert to percentage

To convert \( \frac{25}{4} \) into a percentage, we can divide 25 by 4:

\[ R = 6.25 \]

Thus, the rate of interest per annum is:

\[ R = 6.25\% \]

### Final Answer:
The rate of interest per annum is **6.25%**.

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