To calculate the total amount after a year when ₹12,000 earns 30% interest, you can follow these steps:

1. Calculate the interest:

$\text{Interest} = \text{Principal} \times \text{Interest Rate}$

Substituting the given values:

$\text{Interest} = 12,000 \times \frac{30}{100} = 12,000 \times 0.30 = 3,600$

2. Calculate the total amount:

$\text{Total Amount} = \text{Principal} + \text{Interest}$

Substituting the calculated interest:

$\text{Total Amount} = 12,000 + 3,600 = 15,600$

So, the total amount after a year is ₹15,600.

Would you like more details or have any questions?

Here are 5 related questions to consider:

1. How does the interest amount change if the interest rate increases to 40%?
2. What would be the total amount if the principal was ₹20,000 at the same interest rate?
3. How can you calculate the principal if the total amount and interest rate are known?
4. What is the formula to calculate the interest if the principal and total amount are known?
5. How does compound interest differ from simple interest in calculating the total amount?

Tip: Understanding the percentage of interest is crucial for calculating the correct interest amount and total sum.