added my solution

bonus.py

@@ -0,0 +1,13 @@
+my_sentence = "Success is built on daily discipline, quiet persistence, " \
+"and the courage to keep going when progress feels invisible"
+
+word = "courage"
+
+print("Length of my_sentence:",len(my_sentence))
+print("first occurrence index:",my_sentence.index(word))
+print("number of occurrences:",my_sentence.count(word))
+print("uppercase version:",my_sentence.upper())
+print("lowercase version:",my_sentence.lower())
+my_new_sentence = my_sentence.replace(word, "perseverance")
+print("new sentence:", my_new_sentence)
+print("last character of my_sentence:", my_sentence[-1])

cashier.py

@@ -0,0 +1,21 @@
+price:float = 2.99
+quantity:int = 3
+tax_rate:float = 0.075
+
+# To Calculate subtotal
+subtotal:float = price * quantity
+
+# To Calculate tax
+tax:float = subtotal * tax_rate
+
+# To Calculate total cost
+total:float = subtotal + tax
+
+# To print the subtotal, tax, and total
+print(f"Price of item: ${price:.2f}")
+print(f"Quantity: {quantity}")
+print(f"Tax rate: {tax_rate:.1%}")
+print()
+print(f"Subtotal: ${subtotal:.2f}")
+print(f"Tax: ${tax:.2f}")
+print(f"Total: ${total:.2f}")