Răspuns :
f+b=120
f=20b/100
20b/100+b=120
20b+100b=12000
120b=12000
b=100
f+100=120
f=20
f=20b/100
20b/100+b=120
20b+100b=12000
120b=12000
b=100
f+100=120
f=20
NOT X-NR BARBATILOR
Y-NR FEMEILOR
X+Y=120
X=20Y SUPRA 100
20Y + 100Y= 12000
120Y=12000
X=100
Y=20
Y-NR FEMEILOR
X+Y=120
X=20Y SUPRA 100
20Y + 100Y= 12000
120Y=12000
X=100
Y=20