Răspuns :
620:4=155
155x3=465
465:60=7,75 ceea ce rezulta 8 min si 15 sec
4m---------3s
620m------xs
4x=1860
x=1860:4
x=465 secunde
465:60=7 minute si 45 de secunde
620m------xs
4x=1860
x=1860:4
x=465 secunde
465:60=7 minute si 45 de secunde