On third of 60,000=20,000
selling price of 13=20,000+30%×20,000
=26,000
profit =6000
SP of another 13=20,000+20%/100×20,000
SP =24,000
profit =4000
Remaining watches =60,000−(20,000+20,000)
=20,000
SP of remaining wathes =20,000−5100×20,000
SP =19,000
Loss =1000
Total profit =(6000+4000)−1000
=9,000
Total CP =60,000
Profit loss percentage =900060,000×100
=15%
∴ profit loss percentage =15%