Weight of a peck of water.
A peck is a unit of dry measure, but it is still possible to answer the question, because a peck occupies a specific amount of space.
1 peck [US] = 2.327 294 378 gallon...
mils means thousandth of an inch
Question makes no sense, you cannot quantify water by a length dimension.
Actually, in my world "mils" is short hand for milliliters. In which case 1mL of water =...