Answer:
a) Kate will produce 100 tomatoes and 0 heads of lettuce.
b) Jim will produce 0 tomatoes and 180 heads of lettuce.
Step-by-step explanation:
As climatic conditions are better for tomatoes at Kate's plot of land, she should choose to grow those because of better quality. Also, production of lettuce per square-foot is lower at Kate's land compared to Jim's (3 heads vs 6 heads of lettuce). So on 20-squire-foot Kate could produce 60 heads and Jim - 120 heads of lettuce (2x more). So Kate should avoid production of lettuce due to quality and quantity.
Same explanation can be applied to Jim's production of tomatoes. If Jim produce tomatoes, he will only have quantity of 60 tomatoes at 20-square-foot plot, compare to Kate's 100 tomatoes. So he should avoid production of tomatoes.