>>13362562If the whole field was 1/2 bushel per square yard it would generate 900 bushels.
The marginal gain of a 2/3 productivity compared to 1/2 is 1/6 bushel per square yard.
Since we need 200 more bushels, we need 200 / (1/6) = 1200 square yards to be of the higher productivity. This leads 600 square yards for the lower productivity.
