Răspuns:
(a+b+c+d):4=220
(c+d):2=308
(a+b):2=132
b=a+16
c=a+136
a=? b=? c=? d=?
d=616-c=616-(a+136)=480-a
a+a+16+a+136+480-a=880
2a=248
=> a=124
b=140
c=260
d=356
