Arvind travels from town A to town B, and Surbhi from town B to town A, both starting at the same time along the same route. After meeting each other, Arvind takes 6 hours to reach town B while Surbhi takes 24 hours to reach town A. If Arvind travelled at a speed of 54 km/h, then the distance, in km, between town A and town B is
972
Step-by-Step Solution
This is an after-meeting relative-speed problem β recognisable because two travellers start at the same time from opposite ends, meet somewhere in between, and each is given the time taken to finish the remaining distance after the meeting.
Step 1: Understand what "after meeting" means.
Before meeting, Arvind covers the distance from A to the meeting point, and Surbhi covers the distance from B to the meeting point, both in the same time . After meeting, Arvind covers the remaining distance (B to meeting point, which Surbhi had already covered) in 6 hours, and Surbhi covers the remaining distance (A to meeting point, which Arvind had already covered) in 24 hours.
Step 2: Write the two key equations.
Let km/h be Arvind's speed and be Surbhi's speed, and the time until they meet.
Step 3: Divide (i) by (ii) to find the speed ratio.
So km/h.
Step 4: Find the meeting time .
There is a useful shortcut here: where are the two after-meeting times.
(You can also verify this directly from equation (ii): .)
Step 5: Find the total distance.
Answer: 972 km.
Common trap: stopping after finding only one traveller's pre-meeting distance (like ) β that's only half the journey. The full distance needs both travellers' pre-meeting distances added together, i.e. .