Set up Pearson's square to find the ratio of maize to sunflower.

The desired DCP content for the ration is 20%.
Maize contains 10% DCP.
Sunflower contains 35% DCP.

The ratio of maize to sunflower is 10 parts maize to 15 parts sunflower.
Ratio (Maize : Sunflower) = 10 : 15.
This ratio can be simplified by dividing both numbers by 5:
Ratio (Maize : Sunflower) = 2 : 3.

Total parts = 2 (maize) + 3 (sunflower) = 5 parts.

Proportion of maize = $\frac{\text{Parts of Maize}}{\text{Total parts}} = \frac{2}{5}$.

Amount of maize = Proportion of maize $\times$ Total ration weight
Amount of maize = $\frac{2}{5} \times 200 \text{ kg}$
Amount of maize = $0.4 \times 200 \text{ kg}$
Amount of maize = $80 \text{ kg}$