Question

Un elev a citit intr o zi 0,2(3) din paginile unei carti , iar a doua zi 60%din rest. Cate pagini are cartea daca a treia zi a citit restul de 138 pagini?

Answer 1

0,2(3)=(23-2)/90=21/90=7/30
x=nr pagini
7x/30= ziua 1
x-7x/30=23x/30=rest
23x/30 *60%=23x/30 *60/100=23x/1 *2/100=46x/100=23x/50=ziua 2
7x/30+23x/50+138=x
35x+69x+20700=150x
46x=20700
x=20700:46
x=450 pagini