Simple interest is calculated using the formula:

$\text{Simple Interest} (SI) = P \times R \times T$

where:

• $P$ is the principal amount (initial sum of money)
• $R$ is the rate of interest per period (usually per year)
• $T$ is the time the money is invested or borrowed for, in periods (usually years)

Example Questions:

1. Finding the Simple Interest:

   • Question: What is the simple interest on $1,000 for 3 years at an annual interest rate of 5%?
   • Solution: $SI = 1000 \times 0.05 \times 3 = 150$

2. Finding the Principal:

   • Question: If the simple interest on a sum of money at an annual interest rate of 6% for 4 years is $480, what is the principal?
   • Solution: $480 = P \times 0.06 \times 4$
     • $P = \frac{480}{0.06 \times 4} = 2000$

3. Finding the Rate of Interest:

   • Question: If the simple interest on $800 for 5 years is $200, what is the annual interest rate?
   • Solution: $200 = 800 \times R \times 5$
     • $R = \frac{200}{800 \times 5} = 0.05$ or 5%

4. Finding the Time Period:

   • Question: If the simple interest on $1,500 at an annual interest rate of 4% is $240, how many years was the money invested?
   • Solution: $240 = 1500 \times 0.04 \times T$
     • $T = \frac{240}{1500 \times 0.04} = 4$

5. Total Amount Calculation:

   • Question: What is the total amount after 2 years if $500 is invested at an annual interest rate of 3%?
   • Solution: $SI = 500 \times 0.03 \times 2 = 30$
     • Total Amount = Principal + Simple Interest = $500 + 30 = 530$

Would you like more details or have any questions?

Here are 5 questions you might want to ask:

1. How do you calculate simple interest for a given principal, rate, and time?
2. What is the formula for finding the principal if the simple interest is known?
3. How can you determine the rate of interest from the simple interest formula?
4. How do you calculate the time period when the simple interest, principal, and rate are known?
5. What is the total amount including interest after a certain period for a given principal and rate?

Tip: Always ensure the rate and time period are consistent in their units (e.g., both in years) when using the simple interest formula.