A and B are travelling towards each other from the points P and Q respectively. After crossing each other, A and B take 49/8 hours and 8 hours, respectively, to reach their destinations Q and P, respectively. If the speed of B is 16.8 km/h, then the speed (in km/hr) of A is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e 19.2
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Concept |
Application |
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Speed of A/Speed of B = √(TB/TA) Where TB = Time in which B completes the remaining distance TA = Time in which A completes the remaining distance |
Given Speed of B is 16.8 km/h And After crossing each other, A and B take 49/8 hours and 8 hours respectively to reach their destinations Q and P. Hence, Speed of A/16.8 = √[(8 × 8)/49] ⇒ Speed of A/16.8=8/7 ⇒ Speed of A = 8/7 × 16.8 = 19.2 km/hr |