Let's stop arguing and let TEX provide us the right solution.
All three answers :48", 24" and 12 could be correct depending on how you interpret this puzzle.
If the 1/3 submerged in water, is 1/3 of the whole pole then 48" is the right answer as most of you have posted here.
If the 1/3 submerged in water, is 1/3 of the remaining half then 24" is the right answer.
Also, if the part covered in ground represents the remaining 8" part not in water (air + ground), then 12" is the right answer
Why don't we combine them both for the fun of it!
1/2 is in the ground. 1/3 of the remaining 1/2 (1/6) is in the water. Therefore 5/6 of the pole are not directly submerged in water, and measure a total of 8 feet. That makes the total length clearly 9.6 feet!