Chen spent 7 hours at school on Friday he spent 30 minutes at lunch 50 minutes at a school assembly and the rest in class how much time did Chen spend in class

5 hours and 40 minutes would be class

Step-by-step explanation:

We know that the total time is 7 hours, which in minutes would be:

7 * 60 = 420

420 minutes would be class, now, we subtract the other times that are not to be in class and it would be:

420 - 30 - 50 = 340

So we could say that in class it takes 340 minutes, and if we spend hours it would be:

340/60 = 5.67 hours or also 5 hours and 40 minutes would be class.