Karen is packing her backpack for a long-distance hike. She packs 20 pounds of water, 10 pounds of food, and 20 pounds of gear. During her hike, she drinks 2 pounds of water per hour and eats 1/3rd the weight of food per hour as water per hour. How much weight is she carrying after six hours? Let's think first. Chain of thought:
First find the weight of food Karen eats every hour: 2 pounds * 1 / 3 = 2 / 3 pounds food. Then find the total amount of weight Karen's backpack loses per hour she hikes: 2 pounds water / hour + 2 / 3 pound food / hour = 8 / 3 pounds / hour. Multiply this by the number of hours she hikes to find the total amount of weight she loses: 8 / 3 pounds / hour * 6 hours = 16 pounds. Add the weight of all her items to find total starting weight: 20 pounds + 10 pounds + 20 pounds = 50 pounds. Then subtract the weight she loses from the starting weight to find the weight after 6 hours: 50 pounds - 16 pounds = 34 pounds.
Therefore, the answer is 34.