Total fabric purchased: 400 metres at Rs. 60 per metre
Total Cost Price =400×60
=Rs. 24,000
Target profit on the whole transaction: 12%
Target Selling Price =24,000×1.12
=Rs. 26,880
First half sold: 50% of 400 m =200 m
Cost Price of 200 m =200×60
=Rs. 12,000
Profit on first half: 4%
Selling Price of first half =12,000×1.04
=Rs. 12,480
Remaining fabric: 200 m
Cost Price of remaining 200 m =200×60
=Rs. 12,000
Total money needed =Rs. 26,880
Money already collected =Rs. 12,480
Required Selling Price for remaining fabric =26,880−12,480
=Rs. 14,400
Profit on remaining fabric =14,400−12,000
=Rs. 2,400
Profit percentage =12,0002,400×100
=20%
Therefore, the remaining fabric should be sold at 20% profit.