Amanufacturer of skis produces two types: downhill and cross-country. it takes 2 hours to manufacture a downhill ski and 1 hour to manufacture a cross-country ski. the time available for manufacturing is 40 hours. there are 32 hours available for finishing. it takes 1 hour to finish a downhill ski and 1 hour to finish a cross-country ski. if the profit of a downhill ski is $70 and the profit of a cross-country ski is $50, how many of each ski should be produced to maximize profit?