While waiting in line to buy two tacos at 75 cents each and a medium drink for 80 cents, Jordan notices that the restaurant has a value meal containing three tacos and a medium drink all for $2.50. For Jordan, the marginal cost of purchasing the third taco would be:

55 cents

Explanation:

75 cents each for a taco

$1,50 for two tacos (75*2)

80 cents for a medium drink

Total cost = 1.50+0.80=$2.30

Additional taco = 2.30+0.75=$3.05

Value meal = $2. 50

The marginal cost for Jordon to purchase an additional taco instead of the value meal =

3.05-2.50=55 cents