Correct Answer - Option 1 : 25,080

**Given:**

A sum invested at 10% per annum amounts to Rs. 20,947.50 in one year, interest is compounded half-yearly

**Formula used:**

Simple Interest = (P × r × t)/100

Compound interest

⇒ A = P × {1 + (r/100)}^{t}

Where P = Principal

A = Amount

r = Rate of Interest

t = Time

**Calculation:**

The rate of interest is 10% per annum

But the interest is compounded half-yearly

So, rate of interest will become 10/2 = 5%

⇒ 20947.50 = P × {1 + (5/100)}^{2}

⇒ 20947.50 = P × (21/20)^{2}

⇒ P = 20947.50 × (20/21)^{2}

⇒ P = 19000

According to the question, the rate of interest is tripled.

⇒ r = 10 × 3 = 30%

The simple interest for 22/5 years is

⇒ {19000 × 30 × (22/5)}/100

⇒ (19000 × 6 × 22)/100

⇒ 2508000/100 = Rs. 25080

**∴ The simple interest for \(4\frac{2}{5}\) is Rs. 25080.**