A motorbike leaves point A at 1 pm and moves towards point B at a uniform speed. A car leaves point B at 2 pm and moves towards point A at a uniform speed which is double that of the motorbike. They meet at 3:40 pm at a point which is 168 km away from A. What is the distance, in km, between A and B?

1. 364
2. 378
3. 380
4. 388

The motorbike that left A travelled 168 km from 1:00 p.m. to 3:40 p.m., i.e. in 2 2/3 hours or 8/3 hours.

The car that left B, started at 2:00 p.m. and travelled till 3:40 p.m., i.e. for 1 2/3 hours or 5/3 hours.

The car would have travelled 5/8th of the distance as the bike, but since the car travelled at twice the speed, the car would have travelled 10/8th of the distance.

(10/8) x 168 = 210 km

Therefore, total distance between A and B = 168 + 210 = 378 km

The correct option is B.