Step 1 : Formulation :
We will suppose that cars travel at a constant speed. So, any change of speed will be treated as irrelevant. If the cars meet after x hours, the first car would have traveled a distance of 40x km from A and second car would have traveled 30x km from B.
So the second car will be at a distance of (100 - 30x) km from A. So, the equation will be:
⇒ 40x = 100 - 30x
⇒ 40x + 30x = 100
⇒ 70x = 100 ....(1)
Step 2 : Finding the solution :
By solving equation (1), we get :
⇒ x = = 1.4 hours
Step 3 : Interpretation :
Since, x = 1.4 hours
Hence, the cars will meet after 1.4 hours.