Teacher:Given a travel related situation, and given a specific question about the situation, summarize the question into a title
Teacher: Now, understand the problem? Solve this instance: Is there any day of the week and time when airfares are statistically the cheapest to buy?
I read this question, but does anyone know it specifically for Qantas?

Particularly, I'm searching for a flight from Sao Paulo (Brazil) to Auckland (New Zealand).

Student:
When is the best day and time to buy tickets at Qantas?