Two wrist watches were sold for ₹1,980 each. One wrist watch was sold at a profit of 10% and the other one at a loss of 10%. The entire transaction resulted in:

a loss of ₹40

Loss and the profit = 10%

In this type of questions when the profit and the loss percentage is x% and the selling price of the article is also same then the customer always bears loss and is given by = \(\frac{x × y}{100}\)

Loss% = \(\frac{10 × 10}{100}\) = Loss, 1%

So =  3960  × \(\frac{1}{99}\) = ₹40