You are a travel agent, and you sell trips to Edmonton.
Edmonton gets an average of 7 hours of daylight per day in December.
In June, they get an average of 17 hours of daylight per day.
The amount of daylight per day varies sinusoidally throughout the year.
Wang Hao, Indibil, and Mercedes all like the sun.
• Wang Hao requires at least 9.5 hours of daylight per day.
Indibil requires at least 12 hours of daylight per day.
Which months provide Indibil with enough sun to visit Edmonton?