Zack and Tia chess for 50 minutes they put the chessboard away at 11:20 which clock shows the time they started their class game.

10:30

Step-by-step explanation

11:20,

20 minutes after 11, would be 50 (total time)-20(minutes we know after 11). That leaves us with 30 minutes. minutes prior to 11, would be 10:30.

the answer is 10:30 because you can split 50 by 20 and 30, take 20 from 11:20 you're left with 11 o'clock. there's 60 minutes in an hour so take 30 away you have 30, and it was the hour before 11 meaning it's 10:30