Layton in " Economics for Today" defines Price Discrimination as the practice of a seller

charging different costumers different prices for the same product not justified by cost differences. He also states that the conditions for price discrimination

• The seller is a Price Maker
• The seller can separate consumers into market segments- on the basis of price elasticity of demand
• The seller can prevent arbitrage which is buying cheap and then reselling for a higher price.

Use metro trains or Sydney trains to explain any two of conditions that allow them to practice price discrimination.