I'd like to ask a question about producer surplus. Basically I got the concept and how we calculate when a demand or price changes on a graph, but I cannot figure out how I should apply to real life.
I mean, let's say A = 10, B = 20 and Q = 5.
At first the producers accept to sell at the price $10. Is that right?
And the revenue they get would be $10 \cdot 5 = 50 $ but the producers managed to sell at the price of 20 and the revenue they get is $ 20 \cdot 5 = 100$.
And the difference between what the producers get and what the producers would ask for is $100 - 50 = 50$.
But when I calculate producer surplus using graphic (ABC), I get $\frac{(20 -10 ) \cdot 5} { 2 } = 25 $
So I come to different conclusion in real life than when I calculate using graph. Why? Could anyone explain to me please?