###Human: Pirate Rick sailed his ship to a tropical island in search of a site to bury his treasure.  After finding the perfect site, it took him 4 hours to dig up 8 feet of sand under which to bury the treasure.  Once the treasure was buried, he left the island.  Then, a tropical storm came and washed away half of the sand from on top of the treasure.  Next, a giant tsunami wave poured over the island, adding 2 feet of new sand back onto the site of his treasure. When Pirate Rick returned, how long did it take for him to dig up his treasure?, ### Assistant: Pirate Rick digs at a rate of 8 feet of sand per 4 hours, or 8/4=2 feet per hour.
Of the 8 feet of sand that were initially on top of the treasure, the storm washed 8/2=4 feet of sand away.
Thus, after the storm and the tsunami, the treasure was buried beneath 8-4+2=6 feet of sand.
Digging at a rate of 2 feet per hour, Pirate Rick could uncover his treasure in 6/2=3 hours. 
 So the answer is :  3