Răspuns:
Explicație pas cu pas:
300 ha ................5 tractoristi..................9 zile
100 ha..................5 tractoristi..................3 zile
100 ha...................1 tractorist..................3*5 = 15 zile
100 ha..................3 tractoristi...................15 : 3 = 5 zile
800 ha..................3 tractoristi...................5*8 = 40 zile