Răspuns :
6muncitori...........................................30zile
9muncitori............................................x zile
30 zile : 6 muncitori egal 5
5*9 egal 45 zile
45-30≡15 zile
9muncitori............................................x zile
30 zile : 6 muncitori egal 5
5*9 egal 45 zile
45-30≡15 zile