What should be the minimum markup percentage such that after giving a discount of `66(2/3) %`, there will not be a loss?

What will be the net discount (in percentage) after two successive discounts of 40% and 20%?

If the markup percentage of an article is 50% and discount percentage is also 20%, then the profit percentage will be :

By how much above the cost should the goods be marked for sale so that after allowing a trade discount of 20% and a cash discount of 6backslash(1)/(4)%, a net gain of 20% on the cost is made?