Răspuns :
28 pagini.........................7%
x pagini...........................100%
x=[tex]\frac{28x100}{7}[/tex]=> x = [tex]\frac{2800}{7}[/tex]=>x= 400 pagini are cartea
28 pagini.........................7%
x pagini...........................100%
x=[tex]\frac{28x100}{7}[/tex]=> x = [tex]\frac{2800}{7}[/tex]=>x= 400 pagini are cartea