a=norma
ax30% = 30a/100=3a/10 -realizat 1 saptamana
3a/10 x 40%= 3a/10 x40/100=3a/25 a 2-a saptamana
3a/25 x75%=3a/25 x 75/100 = 9a/100
a-3a/10-3a/25-9a/100=980
100a-30a-12a-9a=980x100
49a=98000
a=2000 piese =norma pe luna
2000 x30%=600 piese a realizat in 1 saptamana
600 x40%=240 piese a realizat in a 2-a saptamana
240 x75%= 180 piese a realizat in a 3-a saptamana
verificare 2000-600-240-180=980 piese rest de executat pana la sfarsitul lunii