Răspuns :
120pagini--------------4/7
x pagini----------------7/7
120=4/7
120:4=30
3/7=30*3=90
7/7=120+90=210 pagini are cartea
x pagini----------------7/7
120=4/7
120:4=30
3/7=30*3=90
7/7=120+90=210 pagini are cartea