Answer:
32 inches or 
 feet
 feet
Explanation:
1 foot = 12 inches
2 feet = 24 inches
Initially, the hole was 2 feet deep, after 3 days, the hole sank 8 inches further, so after 3 days, the hole was 2 feet 8 inches deep.
2 feet 8 inches = 24 inches + 8 inches = 32 inches
Now, 
1 inch 
 foot
 foot
Then 
32 inches 
 inches
 inches