Distance=rate .time
The rate of car 1 is 45km/hr
The rate of 2 car is 70/hr
We know that the second car left two hours after the first
If we let car 1 time =x
Then the time of second car=x-2
When two car reach the landmark,
The distance traveled by each will be the same
Therefore let us set up our equation using the formula for distance
Distance of car 1 = 45*x=45x
Distance of 2 car = 70(x-2)
=70x-140
Set these two equals to each other to designate when they reach the landmark
45x=70x-140
-25x=-140
X=140/25=28/5
=5 3/5
The time traveled by car 2 in the same direction
=v-2=(5 3/5-)-2= 3 3/5 hours
After 3 3/5 hours, car will be overtake car 1