a)V=L*l*h
10cm=1dm=0,01dm³
8cm=0,8dm=0,008dm³
1l=1dm³
1=0,008*0,01*h
1=0,00008*h
h=1/0.00008
h=12500
b)S=2ab+2ac+2bc
=2(0,01*12500+0,01*0.008+12500*0.008)
=2(125+0,00008+100)
=2*225,00008
=450,00016
20% din 450,00016= 20/100*450,00016= 1/5* 450,00016=90,000032 din suprafata se utilizeaza pt fabricarea unei cutii