if you one where maths equations confuse you (which they shouldnt)
then in leymans terms
the 1st car has been going for 10 mins at 90km/h,
10 mins is 1 sixth on an hour, and in 1 hour you would travel 90km at 90km/h
so 1 sixth of 90 is 15km
you closing velocity is 10km/h
so it would take 1 and a half hours to catch up
so 1 and a half hours from 2.10 is 3.40