200000x15:100=3000000:100=30000 lei reducerea de 15% la o pereche de adidasi
300000x20:100=6000000:100=60000 lei reducerea de 20% la o racheta
200000+300000=500000 lei o pereche de adidasi+ o racheta
30000+60000=90000 lei reducerea la o pereche de adidasi+ o racheta
500000 lei................................100%
90000 lei................................. x%
x=90000x100:500000=9000000:500000=18%
R: Reducerea totala pentru o pereche de adidasi si o rachete este de 18% .