How do I calculate the luminosity of a Random Beanbag Machine?

[Adrian1234]

Homework Statement

A big drunken alumni tailgate game has an area of 11 ft2. Engineering alumni have constructed a Random Beanbag Machine that uniformly drops beanbags on the surface so that in each second 660 beanbags drop randomly all over the surface. The beanbag luminosity of this machine is

(Value)(Units)

Homework Equations

Luminosity equation? Energy Conservation?

The Attempt at a Solution

I thought it would be just 660/11= 60 b/ft2, but I'm not sure,

 

[mfb]

What is b?

The units don't fit to a luminosity.