Multiple choice

Car A started from Washington at a speed of 40 kmph and two hours later, Car B also started from the same point towards the same destination at a speed of 60 kmph. Car C started following Car B two hours later. If all the three cars reach Washington at the same time, what is the speed of Car C?

  1. 80 kmph

  2. 100 kmph

  3. 108 kmph

  4. 120 kmph

  5. 125 kmph
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Let D be the distance. Time for A = D/40. Time for B = D/60 + 2. Time for C = D/V + 4. Since they arrive at the same time, D/40 = D/60 + 2 => D/120 = 2 => D = 240 km. For C, D/V + 4 = 240/40 = 6 => 240/V = 2 => V = 120 kmph.

AI explanation

Since Car B travels 4 hours at a speed of 60 kmph, the total journey distance is 240 km. Car C starts 4 hours after Car A, and because all cars arrive at the exact same time, Car C's travel time is equal to Car A's travel time of 6 hours minus 4 hours, resulting in 2 hours. Using the formula speed equals distance divided by time, the speed of Car C is 240 divided by 2, which equals 120 kmph.

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