a=numarul de piese
cate piese a lucrat in prima zi ax2/6=2a/6
cate piese a lucrat in a 2-a zi ax3/6=3a/6
cate piese a avut de lucrat
2a/6+3a/6+49=a
2a+3a+294=6a
a=294 piese
a=km
Cat reprezinta un sfert de drum
a/4
Cati km are drumul
a-a/4=120
4a-a=480
3a=480
a=160 km