a+ 25/100 *a = b+ 50/100 * b =c + 20/100 * c
a+a/4 = b+b/2 = c+c/5 aducem la acelasi numitor
20a +5a = 20b +10b = 20c +4c
25a =30b = 24c
a=30b/25= 6b/5
24c=30b
c=30b/24= 5b/4
a+b+c=345
6b/5 + b + 5b/4 =345 aducem la acelasi numitor
24b +20b+ 25b =6900
69b =6900
b=100
c=5*100/4=5*25= 125
a=6*100/5= 6*20=120