1.
250000 *10%=25000
250000+25000=275000
275000 *10%=27500
275000-27500=247500 lei
2.
100%-40%=60%
pret dupa reducere 60%x=60x/100
60x/100 + 60x/100*p%=x :x
60/100 +60*p%/100=1
60+60*p%=100
60*p%=40
p%=40/60=0,(6)=66,(6)%
3.
x=25%y y=100x/25 =4x
x=20%z z=100x/20 =5x
x+y+z=30
x+4x+5x=30
10x=30
x=3
y=4*3=12
z=5*3=15