Question 1093726
The volume of your vessel is L x W x h (length x width x height):
20 x 15 x h = 48
300 x h = 48 
since we have centimeters on one side and meters in the other, let's convert the centimeters to meters
3 x h = 48
h = 48/3 = 16 meters (this is a tall and skinny tube!)
The area in contact with the water:
20 x 15 . . . = 300
2(20 x 1600) = 64000
2(15 x 1600) = 48000
Total . . . .---------------
. . . . . . . = 112,300 square cm or 1123 square meters