Problema 1
a) Reducere cu 15%=15/100=0,15
725-725×0,15=725(1-0,15)=725×0,85=616,25
b) Scumpire cu 10% a vechiului pret
10%=10/100=0,1
725+725×0,1=725(1+0,1)=725×1,1=797,5
Scumpire cu 10% a pretului rezultat dupa reducere:
616,25+625,25×0,1=625,25(1+0,1)=625,25×1,1=687,775
2.
a) Fie pretul intial x
Scumpire cu 20%⇒x×1,2
Ieftinire cu 10% ⇒(x×1,2)×0,9=x×1,08
1,08x=118800
x=188800:1,08=174815
b) 174815-------------100%
188800-------------x%
x%=188800×100:174815
x%=108%