CAT 2015 Quantitative Ability

A shopkeeper sold 10 items, all of which are of the same cost price, such that profit percentage on no two item is the same The profits made on the given items were in an arithmetic progression If the profit percentage of the item the selling price of winch is 4th highest and the item the selling price of which is 7th highest were 13 % and 10 % respectively, find the profit percentage on the whole.