Răspuns :
In total au coborat 4×5=20 elevi, deci la inceput erau 16+20=36 elevi.
daca in fiecare statie au coborit cate 4, in 5 statii 4×5=20 elevi
au ramas 16, deci in total 20+16=36 elevi
au ramas 16, deci in total 20+16=36 elevi