Question

A car passes a landmark on a highway traveling at a constant rate of 45 kilometers per hour. Two hours later, a second car passes the same landmark traveling in the same direction at 70 kilometers per hour. How much time after the second car passes the landmark will it overtake the first car?

Answer 1

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