A copy machine makes 60 copies per minute.
The second copy machine makes 80 copies per minute.
the second machine starts making copies 2 minutes after the first machine starts.
Both machines stop making copies 8 minutes after the first machine started.
Together, the 2 machine made how many copies?
The first machine ran for the entire 8 minutes, so it made 8×60 or
480 copies. The second machine ran for only the last 6 of the 8 minutes,
so it made 6×80 or 480 copies also. So the total number of copies is
480 + 480 = 960 copies.
Edwin