Process costing - transferred-in costs, weighted-average method, P17 27

[@Tu_Minh]

You saved me last minutes TT

[@nobinpradhan9235]

If in the first place, the transferred out units from blending Dept. are 90, then how come in the table (solution), 100 units are appearing in the column of "Transferred in"as COMPLETED AND TRANSFERRED OUT? Likewise, EWIP is shown as 40. Doesn't this suggest that 100 units completed PLUS 40 units are incomplete (EWIP) add upto 140?If yes, then there is a contradiction . The problem tells us that 90 units were transferred out from Blending dept. to Finishing dept. in the beginning. So 90 transferred out from Blending to Finishing , on the one hand and completed in Finishing dept. 90 PLUS 50 are Ending WIP . The arithmetic is difficult to understand.Please explain.