Răspuns:
a+b+c+d=3900
a |.....|
b |.....|......|
c |......|......|......|
d |.....|.......|......|......|.......|.......|
aflam primul numar:
3900:12=325(a)
Aflam al doilea numar:
325×2=650(b)
Aflam al treilea numar:
325×3=975(c)
Aflam al patrulea numar:
325×6=1950(d)
v:325+650+975+1950=3900(suma)
corect
Coroana!!!