Assuming that X meters are made the next day, then 0.9X meters are made the first day and 1.2X meters are made the third day. It can be seen from the topic "Grade Three is 30 meters more than Grade One" that 1.2X-0.9X=30.

X= 100, 90m on the first day, 100m on the second day and120m on the third day.