demand function:

p-18=(140-x)/20

Calculate the consumer surplus if the shirts are sold for $16 each.

To calculate the consumer surplus, we need to find the area under the demand curve and above the price line ($16 in this case).

The demand function in this case is given by: p - 18 = (140 - x) / 20

First, we need to determine the quantity demanded when the price is $16. We can substitute p = 16 into the demand function and solve for x:

16 - 18 = (140 - x) / 20

Simplifying:

-2 = (140 - x) / 20

Multiplying both sides by 20:

-40 = 140 - x

Rearranging the equation:

x = 140 + 40
x = 180

Therefore, when the price is $16, the quantity demanded is 180 shirts.

Next, we calculate the consumer surplus by finding the area under the demand curve and above the price of $16. Since the demand curve is linear, the area of the consumer surplus triangle can be calculated using the formula: CS = 0.5 * base * height

The base of the triangle is the quantity demanded (x = 180), and the height is the difference between the price and the minimum possible price (p = 16 and p = 0, respectively). So, the consumer surplus (CS) can be calculated as:

CS = 0.5 * 180 * (16 - 0)
CS = 0.5 * 180 * 16
CS = 0.5 * 2880
CS = 1440

Therefore, the consumer surplus is 1440 when the shirts are sold for $16 each.