Răspuns :
regula de trei simpla cu marimi invers proportionale
5z........18 zile
6z..........x zile
x=5*18/6=15zile
5z........18 zile
6z..........x zile
x=5*18/6=15zile
5 zugravi .............18 zile
6 '' ................x ''
x =5*18/6 =15 zile
6 '' ................x ''
x =5*18/6 =15 zile