Linear Graphs in Real Life Problems

Mr. Tan drove from home to Changi Airport to pick up his friend. On his way to the airport, he stopped by at a petrol station to refuel his car. After arriving at the airport, Mr. Tan waited for his friend. Then they went to a restaurant to have dinner. The distance-time graph below shows Mr. Tan’s entire journey till he reached the restaurant. You may assume all locations lie on a straight line.

1. Find the distance from the restaurant to Mr. Tan’s home.
2. Find, in minutes, the time Mr Tan spent
   1. refuelling his car,
   2. waiting for his friend at the airport.
3. Find the gradient of each of the following line segments, and state clearly what each gradient represents.
   1. \(OA\),
   2. \(AB\),
   3. \(BC\),
   4. \(DE\).