If someone sells 271 bags of popcorn and made 447 dollars, with a large bag costing 3 dollars and a small one costing 1 dollar. How many bags did they sell?

Number of small bags = x

Number of large bags = y

x + 3y = 447

x + y = 271

Subtract the second equation from the first to get

2y = 176

y = 88

x = 183

I'm assuming you meant to say 'How many small/large bags did they sell?'

So

183 small bags and 88 large bags

Let x be big bag, y be small bag
X+y= 272
3x+y=447
Solve for y use substitution or subtraction which ever is best for you.
In my case I use subtraction, solve for y.
Subtract y on both equation.
You will get -2x= -175, x = 87.5. Plug in 87.5 solve for y. 184.5

120 cubic feet is the answer.