1) 24/100•X=12
12/50•X=12
6/25•X=12
X=12:6/25
X=12•25/6
X=300/6
X=50 probleme in total
100%-24%=76%
2)a-b=52
b=20/100•a
b=1/5•a
a-a/5=52
5a-a=260
4a=260
a=260/4
a=65
b=65/5
b=13
3)a+b+c=110
a=30/100•b =>3b/10
c=25/100•a => a/4
3b/10+b+a/4=110
3b/10+b+(3b/10)/4=110
3b/10+b+3b/10•1/4=110
3b/10+b+3b/40=110
12b+40b+3b=4400
55b=4400
b=80
a=(3•80)/10
a=240/10
a=24
c=24/4
c=6