Answer:
Third-degree price discrimination
Step-by-step explanation:
Price discrimination is defined as the phenomenon where a single supplier of goods and services charges different prices in different markets on the same product.
Third-degree price discrimination occurs when different prices are charged to different customers for the same product. Customers are grouped by age, sex, location, and time of use.
In the given instance discrimination was based on age. One price was given for children and another for adults.
This is a very common type of price discrimination.