A rides his bicycle at 15 km/h, while B starts his ride after 6 hours to catch with a speed of 25 km/h. Time taken by B to catch A (in hours) is:
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 9.
Distance A travels before B starts = 15 × 6 = 90 km
Let the time B takes to catch A = x hours
So, 90(15 + x) = 25x
⇒ 90 + 15x = 25x
⇒ 10x = 90
⇒ x = 90/10 = 9
Therefore, the time taken by B to catch A is 9 hours.