Answer:
$250 is the change in social surplus attributable to the increase in the toll
Explanation:
Suppose the government increase in toll on a certain stretch of highways by this caused a dead-weight loss occur and then resulting full in the number of cars using the highway.
Dead-weight loss = (0.5) (0.50-0.40) (50,000-45,000)
Dead-weight loss = 0.5 * 0.10 * 5000
Dead-weight loss = $250
The increase paid by other remaining drivers (0.50-0.40)(40,000) can be viewed as transfer from drivers to the government.