A nut store normally sells cashews for 4 00 per pound and peanuts for 1 50 per pound But at the end of the month the peanuts had not sold well so in order to sell 90 pounds of peanuts th manager decided to mix the 90 pounds of peanuts with some cashews and sell the mixture for 2 50 per pound How many pounds of cashews should be mixed with the peanuts to ensure no change in the revenue