A cloth merchant sold half of his cloth at 40% profit, half of remaining at 40% loss and the rest was sold at the cost price. In the total transaction his gain or loss will be =?

Question: A cloth merchant sold half of his cloth at 40% profit, half of remaining at 40% loss and the rest was sold at the cost price. In the total transaction his gain or loss will be =?

Solution:
Let, total price 100 taka

Half at 40% = 50 + 50 × 0.4
= 70 taka

half of remaining at 40% loss = 25 - 25 × 0.4
= 15 taka

rest = 25 taka

Total = 70 + 25 + 15
=110 taka

In the total transaction his gain = 110 - 100
= 10