Multiple choice

A car is running at a speed of 64 km/h to cover a certain distance in 40 min. At what speed should the car run to reduce the time of the journey to 30 min?

  1. 74.65 km/h

  2. 84.78 km/h

  3. 54 km/h

  4. 85.33 km/h
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D Correct answer
Explanation

Distance = 64 km/hr * (40/60) hr = 64 * 2/3 = 128/3 km. New speed = (128/3) / (30/60) = (128/3) * 2 = 256/3 = 85.33 km/hr.

AI explanation

Using the constant distance formula S1 multiplied by T1 equals S2 multiplied by T2, we substitute the given values. The calculation is 64 km/h multiplied by 40 min divided by 30 min, which results in 2560 divided by 30. This yields the required new speed of 85.33 km/h. The car should run at 85.33 km/h.

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