A researcher wants to find out whether campers prefer cotton or nylon sleeping bags. A troop of boy campers tried cotton and a troop of girl campers tried nylon sleeping bags. The sleeping bags were rated for softness and warmth. The confounding variable is

At the county fair, animals are judged for the quality of their breeding and health. the animal pens are arranged in an array, with one animal in each pen. a barn can hold at most 10 rows of pens and at most 6 pens in each row, with room for people to walk around them. what different ways can the planners of the county fair arrange the pens for the horses and cows in the same barn?