Math does work out after all

So, two of the smartest people I know couldn't figure it out, but it's ok they're better with english anyway ;)

I figured it out though. You do need both the weight and the volume to figure it out.

First each gallon weighs 7 lbs, so you take 42 gallons and multiply it by 7lbs. = 294lbs

The tricky part is that it says each cubic foot is 52lbs. They're trying to trick you into associating cubic feet with lbs, but really they're two different variables being used for a conversion from one way of measuring a material like converting a persons pay check into hours and hourly rate over the course of a large time frame (large time frame being the 42 gallon barrel).

So, what's this mean? A 42 gallon barrel weighs 294lbs, but it's cubic feet is a percentage of that weight. 294/52, as it takes 52 lbs of material to compose 1 cu ft the correct answer is 5.7 as the math turns out the whole number is: 5.653846153846153846153846153846(infinitely in the 153846 pattern)

and because they rounded up the correct answer is A, 5.7.