At the moment when two cars meet, the distance between them is116+124 = 240 (meters).

If there is a person at the rear of every car and two people walk in opposite directions, their speed is: 14+ 10=24 (m/s).

240/24= 10 (seconds) ... They met after 10 seconds.

The moment when they meet is the moment when the rear of the car separates, so it takes 10 second from the moment when the two cars meet to the moment when the rear of the car separates.