To solve this, it's easiest to assume a convenient Cost Price (C.P.) of ₹100. The goal is to find how much the Marked Price (M.P.) is above this C.P.

1. Calculate the Selling Price (S.P.):

   The trader earns a profit of 11.11%. It's helpful to know that 11.11% is the decimal equivalent of the fraction 1/9.

   Profit = (1/9) * C.P. = (1/9) * 100 = ₹11.11... S.P. = C.P. + Profit = 100 + 11.11... = ₹111.11...

   (For precision, we can use the fraction: S.P. = 100 * (10/9) = 1000/9)

2. Calculate the Marked Price (M.P.):

   The Selling Price is the price after a 20% discount on the Marked Price. This means the S.P. is 80% of the M.P.

   S.P. = M.P. * 0.80

   To find the M.P., we rearrange the formula:

   M.P. = S.P. / 0.80 M.P. = (1000/9) / 0.80 = (111.11...) / 0.80 ≈ ₹138.89
3. Calculate the Markup Percentage:

   The markup is the percentage difference between the Marked Price (what it's listed for) and the Cost Price (what the trader paid).

   Markup Amount = M.P. - C.P. = 138.89 - 100 = ₹38.89 Markup % = (Markup Amount / C.P.) * 100 Markup % = (38.89 / 100) * 100 = 38.89%

Final Answer: The trader marked his goods 38.89% above the cost price.