Racer A and racer B run a race of 18 km on a circular track of length 800 m. Both complete one round in 200 sec and 250 sec, respectively. After how much time from the start will the faster person meet the slower person for the last time?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 4000 sec.
Given that
Racer A and Racer B run a race of 18 km on a circular track of length 800 m
Both complete one round in 200 seconds and 250 seconds, respectively
⇒Total numbers of rounds in the race = 18000/800 = 22.5 rounds
⇒A and B meet for the first time at LCM (200, 250) = 1000 seconds
⇒Fourth meeting will be at = 4 × 1000 = 4000 seconds
⇒For the next morning, the time will be 5000, which is impossible as A completes the race in 4500 sec
⇒But for the 22.5 rounds, A completes the race in 4500 seconds.
So, time cannot be more than 4500 seconds.
Hence, the faster person meets the slower person at 4000 seconds.