James can do a farmer's walk with 300 pounds per hand for 20 meters. He can lift 30% more if he only goes 10 meters. In addition, lifting straps give him another 20%. How much can he move with lifting straps for 10 meters if he increases his 20-meter distance without straps by 50 pounds and everything else increases in proportion? Let's think first. Chain of thought:
After the increase, he can lift 300 + 50 = 350 pounds. Decreasing the distance increase the amount he can lift by 350 * .3 = 105 pounds. So he can lift 350 + 105 = 455 for 10 feet. The straps add another 455 * .2 = 91 pounds. So his total weight is 455 + 91 = 546 pounds per hand.
Therefore, the answer is 546.