If each of the 3 volumes consists of 1000 sheets and the sheets are 17 cm by 28 cm, then the lengthwise dimension of each sheet is 28 cm.
The total number of sheets in all 3 volumes would be 3×1000=30003×1000=3000 sheets.
If all the volumes are placed one after the other, lengthwise, then the total length would be 3000×283000×28 cm.
That would be 3000×28=840003000×28=84000 cm.
To convert this into meters (M.K.S system), you would divide by 100 (since there are 100 cm in a meter).
So, 84000 cm=840 m84000cm=840m.
If all the volumes are placed one after the other, lengthwise, the row would reach a length of 840 meters.