Respuesta :

Because 5x6 is 30 that is plenty for 27 kids but 5x5 is only 25, that is not enough for 27 kids. 
we need 6 packs because it will have 30 pencils. Enough for 27 students. If it is 5 pack, it won't work because it will only have 25 pencil, which is not enough for 27 students