import tkinter as tk
from tkinter import messagebox

def calculate_simple_interest():
    try:
        principal = float(principal_entry.get())
        rate = float(rate_entry.get())
        time = float(time_entry.get())

# Calculate simple interest
        simple_interest = (principal * rate * time) / 100

# Display the result
        result_label.config(text=f"Simple Interest: {simple_interest:.2f} USD")

except ValueError:
        messagebox.showerror("Error", "Please enter valid numeric values for all fields.")

# Create the main window
root = tk.Tk()
root.title("Simple Interest Calculator")

# Create and place widgets
principal_label = tk.Label(root, text="Principal Amount:")
principal_label.pack()

principal_entry = tk.Entry(root)
principal_entry.pack()

rate_label = tk.Label(root, text="Interest Rate (%):")
rate_label.pack()

rate_entry = tk.Entry(root)
rate_entry.pack()

time_label = tk.Label(root, text="Time (years):")
time_label.pack()

time_entry = tk.Entry(root)
time_entry.pack()

calculate_button = tk.Button(root, text="Calculate Interest", command=calculate_simple_interest)
calculate_button.pack()

result_label = tk.Label(root, text="")
result_label.pack()

# Run the Tkinter event loop
root.mainloop()

O Level Exam : Practical Question

🖥 Output: