One of the best way to solve the profit and loss or discount questions are by using percentages and fractions.
For e.g :
In question it is given that marked price is 10% above the cost price and there is a loss of 1%. Then calculate dicsount percentage.
Firstly, Let the CP be 100
Now we can write MP/CP= 110/100 ( MP IS 10% above the Cp)
SP/CP=99/100 ( loss of 1% is there)
Discount= ( MP- SP)/MP
(110-99)/110
=10%