Question

Dupa 2 ieftiniri succesive,prima de 10% ,iar a doua de 5% ,un produs costa 85,5 lei,Aflati pretul initial al produsului.

Answer 1

x-suma intiala
10% din x= 10/100 *x=1/10*x= x/10-prima reducere
x-x/10=   10x-x/10=  9x/10-restul
5%din 9x/10= 5/100 *9x/10= 1/20 * 9x/10= 9x/200- a doua reducere

9x/10-9x/200= 180x-9x/200= 171x/200
171x/200 =85,5
x=200*85,5/171=  17100/171=100
x=100lei