x=cantitatea de cartofi
x/3= client 1
x-x/3=2x/3=rest
2x/3 :2+1,5=x/3+1,5=client 2
x/3+x/3+1,5+13,5=x
2x/3+15=x
2x+45=3x
x=45 kg cartofi
45-13,5=31,5 kg au cumparat primii 2 clienti
45 ×1/3=15 kg primul client
45-15=30 kg rest dupa prima vanzare
30 × 1/2 +1,5=15+1,5=16,5 kg clientul al 2-lea