1 Notam nr cu abcd barat , a<b<c<d .
d=c+2=b+2+2=a+2+2+2
a+b+c+d=20 => a+a+2+a+4+a+6=20
4a+12=20
4a=8 => a=2 , b=4 ,c=6,d=8
abcd poate fi 2468 , 2486 , 2648,2684 ,2846 , 2864 , 4268, 4286 , ... , 8642
2)
primul primeste 192/8= 24scaune
al doilea primeste 192/8*2=48 scaune (2/8=1/4)
al treilea primeste 192*4/16=48 scaune (4/16=1/4)
al patraulea laborator primeste 192-24-48-48=72 scaune