notam cu x- nr de pagini din prima zi
a doua zi=x+5
a treia zi =x+10
a patra=x+15
a cincea=x+20
a sasea=x+25
a saptea=x+30
total sapte zile 7x+5+10+15+20+25+30=7x+105=175
7x=70
x=10
In cinci zile citeste x+x+5+x+10+x+15+x+20=5x+50=50+50=100
dupa 5 zile a ajuns la pagina 5+100=105