It takes 20 minutes to get to the airport. If Quincy wants to be at the airport 1 hour and 5 minutes before his flight leaves, it means that the maximum amount of time that Quincy has before left before she gets to the airport is
1 hour + (20 + 5) minutes = 1 hour 25 minutes.
His flight leaves at 9:50 A.M. This means that the latest time that Quincy can leave for the airport would be 9:50 A.M. - 1:25
If it takes 20 minute to get to the airport, and he wants to be there an hour and 5 minutes before his flight leaves, we have to subtract the time he leaves (9:50) by 1 hour and 5.
9:50 - 1 hour and 5 minutes.
9:50 - 65 minutes.
9:50 - 65 = 8:45.
Which means he must be at the airport at 8:45.
BUT,
The question is asking for the latest time that Quincy can LEAVE for the airport, which means it's 8:45 - 20 minutes, since it takes 20 minutes to get to the airport:
