The Instalment Payment System is a method of purchasing goods where:
1. Ownership and Payment: The buyer takes immediate possession of the goods but pays the price in smaller, regular installments over a period of
time.
2. Interest Charges: In many cases, interest is charged on the remaining balance, increasing the total cost.
3. Example: High-value goods like cars, furniture, or electronics are often sold using this system to make them affordable for customers.
This system allows buyers to enjoy the benefits of ownership while spreading the financial burden over time. However, failure to pay installments can lead to repossession of the goods by the seller.
On the day of her examination, Riya sharpened her pencil from both ends as shown below. 
The diameter of the cylindrical and conical part of the pencil is 4.2 mm. If the height of each conical part is 2.8 mm and the length of the entire pencil is 105.6 mm, find the total surface area of the pencil.