Given that a merchant purchases a cloth at a rate of Rs.\(100\) per meter and receives \(5\) cm length of cloth free for every \(100\) cm length of cloth purchased by him.
So, the cost price of \(105\) cm clothes is \(100\) rupees.
Subsequently, the merchant sets the selling price of \(100\) cm of cloth at \(110 \)rupees but applies a \(5\%\) discount and he cheated his customers by giving \(95\) cm length of cloth for every \(100\) cm length of cloth purchased by the customers.
Therefore, the selling price of \(95\) cm clothes \(=110\times\frac {19}{20}\)
And, the selling price of \(105\) cm clothes \(=115.5\) rupees.
Hence, the profit \(=15.5\%\)
So, the correct option is (D): \(15.5\%\)