Student: A car finishes a journey in ten hours at the speed of 80 km/hr. If the same distance is to be covered in eight hours how much more speed does the car have to gain?\nOptions:\n(A) 8 km/hr\n(B) 10 km/hr\n(C) 12 km/hr\n(D) 16 km/hr\n(E) None of these.
Another student: Let's say, hmmm...

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Distance covered by the car = 80 × 10 = 800 km\n\ Speed = 800⁄8 = 100 km/hr\n\ Speed gain = 100 – 80 = 20 km/hr Final answer: (E).
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