###Human: At school today, Charlize was 20 minutes late. Four of her classmates were each ten minutes late than she was. What's the total time for which the five students were late?, ### Assistant: If Charlize was 20 minutes late, each of her friends was 20+10 = 30 minutes late.
The total time for which Charlize's friends were late was 4*30= 120 minutes.
Together with Charlize, the three friends were 120+20 = 140 minutes late. 
 So the answer is :  140