Multiple choice

Mr. A has to catch a flight whose boarding time is 10:00 am. He calculated that if he has to reach there on time, he will have to drive his car at a speed of 40 km/hr from his home and if he has to reach the airport 2 hours early, then he will have to drive at speed of 60 km/hr. Calculate the speed at which he has to travel such that he reach the airport one hour early?

  1. 48 kmph

  2. 50 kmph

  3. 52.5 kmph

  4. Cannot be determined
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let D be the distance. Time at 40 km/hr is D/40. Time at 60 km/hr is D/60. The difference is 2 hours: D/40 - D/60 = 2. D/120 = 2, so D = 240 km. To reach 1 hour early (compared to 40 km/hr), he needs to take (D/40 - 1) hours. Time = 6 - 1 = 5 hours. Speed = 240 / 5 = 48 km/hr.

AI explanation

Let the usual time taken to reach exactly on time be t hours; using the distance formula Distance = Speed x Time, we equate the distances for both scenarios: 40t = 60(t - 2). Solving this equation yields t = 6 hours, making the total distance 240 kilometers. To arrive one hour early, he must complete this 240 kilometer journey in 5 hours. The required speed is 240 / 5 = 48 kmph. The required speed is 48 kmph.

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