In terms of "ratio units", the original ratio of flour in the two sacks is
.. 8 : 6 . . . . . . . . we choose 8 so we can transfer 1/8 of the amount easily.
and the ratio after the transfer is
.. 7 : 7 . . . . . . . . after the transfer the first sack will have 7, so the second must as well.
There are 14 ratio units here, so each must stand for 10 lb of flour
The original amount of flour in the two sacks is 80 lb and 60 lb.