A salesman sells two shirts at BDT 594 each. On one he gains 10% and on the other, he loses 10%. Find his gain or loss percent on the whole.

At 10% profit, The cost price of the first shirt
= 100/(100 + 10) × 594
= Tk. 540

At 10% loss, The cost price of the second shirt
= 100/(100 - 10) × 594
= Tk. 660

Now, the total cost price of two shirts
= 540 + 660
= Tk. 1200

and the total sell price of two shirts
= 594 × 2
= Tk. 1188

Loss = 1200 - 1188
= Tk. 12

Percentage of loss = (12/1200 × 100)%
= 1%
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Shortcut:
Loss percentage = (common gain or loss/10)% = (10/10)% = 1%
[ When a salesman sells two shirts at same price each and on one there is gain is equal to on other there is loss in percentage, then there shall be always loss percent on the whole and loss percentage will be (common gain or loss/10)% ]