Answer:
$81.60
Explanation:
A 20% markdown means that the chairs were sold at 80% of the original cost.
Original cost = $102
markdown = 20%
Cost after markdown = original cost* (1-markdown)
Cost after markdown = 102 *(1 - 0.20)
= 102*0.80
= 81.6
Therefore, the 4 chairs were sold at a total cost of $81.60