Q.Write a Python program to calculate the amount payable if money has been lent on simple interest. Principal or money lent = P, Rate = R% per annum and Time = T years. Then Simple Interest (SI) = (P x R x T)/ 100.
Amount payable = Principal + SI.
P, R and T are given as input to the program.

This is a plain theory question asking for a Python program that computes simple interest and the total amount payable.

The program reads three inputs—principal $P$, rate $R$ (percent per annum), and time $T$ (years)—then applies the formula $\text{SI} = \frac{P \times R \times T}{100}$ and adds it to the principal to find the amount payable.

# Input: Principal, Rate, Time
P = float(input("Enter Principal (P): "))
R = float(input("Enter Rate (R% per annum): "))
T = float(input("Enter Time (T years): "))

# Calculate Simple Interest
SI = (P * R * T) / 100

# Calculate Amount Payable
Amount = P + SI

# Output
print(f"Simple Interest: {SI}")
print(f"Amount Payable: {Amount}")

Key lines:

• float(input(...)) reads each value as a floating-point number, allowing decimal inputs for principal, rate, or time.
• SI = (P * R * T) / 100 directly implements the simple-interest formula.
• Amount = P + SI adds the interest to the principal to get the total repayment. …

Why this approach works

Simple interest is a linear calculation: the interest earned each year is a fixed percentage of the original principal, and it does not compound. The formula $\text{SI} = \frac{P \times R \times T}{100}$ captures this directly—$R$ is the annual rate as a percentage, so dividing by 100 converts it to a decimal multiplier, and multiplying by $T$ gives the total interest over all years.

The amount payable is simply the sum of what was borrowed (the principal) and the interest accrued. This is a straightforward arithmetic task: take three inputs, apply the formula, and display the result.

The program

# Read inputs from the user
P = float(input("Enter the principal amount (P): "))
R = float(input("Enter the rate of interest per annum (R): "))
T = float(input("Enter the time period in years (T): "))

# Calculate Simple Interest
SI = (P * R * T) / 100

# Calculate Amount Payable
amount_payable = P + SI

# Display the results
print(f"Simple Interest (SI): ₹{SI:.2f}")
print(f"Amount Payable: ₹{amount_payable:.2f}")

Key lines explained

P = float(input(…))

We use float() because principal, rate, and time can all be decimal values (for instance, a rate of 7.5% or a time period of 2.5 years). Reading them as floats ensures the calculation handles fractional inputs correctly.

SI = (P * R * T) / 100

This is the direct translation of the simple interest formula. The rate $R$ is given as a percentage, so dividing by 100 converts it to the actual fraction of the principal earned per year.

amount_payable = P + SI

The total amount to be repaid is the original loan plus the interest. This is the final value the borrower must return.

print(f"… ₹{SI:.2f}")

The .2f format specifier rounds the output to two decimal places, which is standard for currency. The f-string makes the output readable and professional. …