Elias has to select one shirt, one pair of pants, and one pair of shoes. If he selects at random from his 8 shirts, 4 pairs of pants, and 3 pairs of shoes, and all his shirts, pants, and shoes are different colors, what is the likelihood that he will select his red shirt, black pants, and brown shoes? Find the total production of each company after d days. Factory X starts with 18,000 units and can produce 120 units per day, so its production after d days will be 18,000 + 120d. Factory Y starts with only 14,500 units, but can produce 155 units per day, so its production after d days will be 14,500 + 155d. Since you are looking for the number of days after which the total production of each factory will be equal, set the two equations equal to one another: 18,000 + 120d = 14,500 + 155d ;