Answer: it is now 4 inches.
Explanation:
The first day,there were 18inches. The second day it melted 2 inches. This means that the number of inches in the second day is 18 - 2 = 16 inches.
The next day it melted 4 inches. This means that the number of inches in the third day is 16 - 4 = 12 inches.
The next day, 8 inches of snow fell. This means that the number of inches in the Fourth day is 12 - 8 = 4 inches.