If Abhi travels a certain distance at the speed of 6 km/h, he reaches his destination 12 min early, but if he travels at 4 km/h, he reaches his destination 10 min late. The speed at which he should travel to reach his destination on time is _______ km/h.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 33/7
| Application |
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Distance = [(Product of speed/difference of speed)] × time difference (in hour) So, Distance = [(6 × 4)/(6 - 4)] × (12 + 10)/60 ⇒ Distance = (24)/(2) × (22)/60 ⇒ Distance = 22/5 ⇒ Distance = 4.4 km |
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Now, Actual time = distance/speed ⇒ Actual time = (4.4/4) - 1/6 ⇒ Actual time = (13.2 - 2)/12 ⇒ Actual time = 11.2/12 |
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Actual speed = Distance/Time = (4.4 × 12)/11.2 = 33/7 km/h |