2020 Quantitative Aptitude - Percentage

A shop owner offers the following discount options on an article to a customer : 1. Successive discounts of 10% and 20%, and then pay a service tax of 10% 2. Successive discounts of 20% and 10%, and then pay a service tax of 10% 3. Pay a service tax of 10% first, then successive discounts of 20% and 10% Which one of the following is correct?

• 1 only is the best option for the customer.
• 2 only is the best option for the customer.
• 3 only is the best option for the customer.
• All the options are equally good for the customer.