a)V=a*b*c; c=[tex] \frac{V}{ab}= \frac{26600 cm^{3} }{20cm*19cm} [/tex]=70(cm)
R/s:inaltimea=70cm
c)15*8=120(ore)-lucreaza un muncitor in 15 zile
20*120=2400(ore) - lucreaza in total 20 de muncitori
10*12=120(ore)-lucreaza un muncitor in 10 zile
120*15=1800(ore)- lucreaza in total 15 muncitori
2400ore...4500piese
1800ore...?piese
1800*4500/2400=3375(piese)