Volume of an iceberg = 7685 cubic feet
Since, density of ice = 0.917 
We have to determine the mass of the ice.
Since density = 
Since the unit of density is in
, first we will convert the density unit in kilogram.
Since, 1 kilogram = 1000 gram
Therefore, density = 
= 0.000917 
Since, the density unit is in cubic centimeter. We will convert it into cubic feet.
1 cubic centimeter = 0.00003531466 cubic feet
Therefore, 0.000917
= 0.000917 x 0.00003531466
= 0.0000000323
.
Now, mass = 
= 0.0000000323
7685
= 0.000248
=0.00025
.
Therefore, the mass of ice is 0.00025
.