Acar approaching an intersection has a 0.1 probability of turning left and a 0.2 probability of turning right. explain why the events are mutually exclusive.

They are mutually exclusive because at intersection car cant turns both ways
as it turns right or go straight or go left.
and both are independent to each other as if car turns left it cant turn right at the same time,vice versa,

First, plot quantity demanded. This will be your demand curve. You do that like this: you see that at the price 4.89, quantity demanded was 311. Plot a point at the coordinates x:311, y:4.89. Same for other prices; plot the 4 other points (for example, the second has coordinates x:388, y:4.29). Now connect those points with a curve. This is your demand curve! Now plot quantity supplied the same way and draw the supply curve. 
Surplus is when quantity supplied is greater than quantity demanded. This happened at prices 5.39 and 5.19. Shortage is when quantity demanded is greater than quantity supplied, which happened at prices 4.29 and 4.89. Equilibrium is when both quantities are the same and the market clears; that happened at the price 5.00.