By how much percent a shopkeeper must mark his goods above its cost price so as by giving 40% discount, he earns a profit of 26%.

110%

C.P. : MRP = (100 - Discount)% : (100 + Profit)%

                =  (100 - 40)% : (100 + 26)%

                =  60% : 126%

                = 10 : 21

C.P. = 10R

MRP = 21R

So, shopkeeper marks up his goods by = \(\frac{21R\;-\;10R}{10R}\)× 100% = \(\frac{11}{10}\) × 100% = 110%