An unscrupulous trader decided to make some extra profit on coffee. He bought one type of coffee powder at $32 a kilo and mixed some of it with a better quality of coffee powder bought at $40 a kilo, and he sold the blend at $43 a kilo. That gave him a profit of 25 per cent on the cost. How many kilos of each kind must he use to make a blend of a hundred kilos weight?