The current market demand for product X is given by Q=19−P where P is price-per-unit in dollars. Suppose that the willingness-to-pay for X goes up by $1 at every unit. Use the new demand to calculate the consumer-surplus if the price is $10 per unit. What is this consumer surplus? (Hint: you may find it helpful to plot the original demand and then apply the increase in willingness-to-pay).