Respuesta :
Let x be additional food item the homeroom B should collect to have greater item per student than homeroom A.
(22 +24 + x) / 16 > (30 + 42 + 21) /24
(22 +24 + x) > 3.875 (16)
X > 16
So they should collect more than 16 food item to have a greater item per student