Ribbon factory has produced a batch of ribbons to be packaged. The first class was packed with 500 bags, the second class was packed with 90% of the first class, and the remaining 2/7 of the third class was completed ahead of schedule. How many bags can this batch of ribbons produced by the ribbon factory hold?

Analysis: 1, number of packages in class 2: 500*90%=450.

2. The rest is 2/7, which means that the number of packets in the first two classes is 1-2/7.

3. To find the total number of 1, first find 1/7 copies and then find 7/7 copies, which is the total number.

4. Formula: (500+500*90%)? ( 1-2/7)= 1330