Question 350513
speed = 60 km/h
time = y hours
distance = speed & time
= 60*y
60y km.
For 60y km 15 litres
1 km 15/60y litres.
...
1km 15/60y litres
120 km  the consumption will be 120*15/60y
=30/y litres
..
total consumption = 15 + 30/y litres