Question

intr-o clasa sunt cu 12 mai multi baieti decat fete iar fetele reprezinta 30%din nr elevilor.Cati elevi sunt in clasa?

Answer 1

B=F+12
F=30(B+F)/100
100F=30B+30F
30B=100F-30F
30B=70F
30(F+12)=70F
30F+360=70F
70F-30F=360
40F=360
F=360/40
F=9
B=F+12=9+12=21