Yes what he or she said because they are correct.
80 km = 80000 m
5 saatte = 300 dk’dir
80000m/300 dk’dir = 266.666667 m/dk’dir
(Yazım yanlışsa kusura bakmayın türkçe bilmiyorum :) )
15, since 16-1=15, and you can use the y-intercepts as points to measure the distance from.
