Question

    A car travels at a speed of 60 km/h for the first 2

    hours, then at 80 km/h for the next 3 hours, and finally at 100 km/h for the last 1 hour. What is the average speed of the car for the entire journey?
    A 75 km/h Correct Answer Incorrect Answer
    B 76.67 km/h Correct Answer Incorrect Answer
    C 72 km/h Correct Answer Incorrect Answer
    D 70.5 km/h Correct Answer Incorrect Answer

    Solution

    Total distance = (60 × 2) + (80 × 3) + (100 × 1) = 120 + 240 + 100 = 460 km. Total time = 2 + 3 + 1 = 6 hours. Average speed = Total distance / Total time = 460 / 6 = 76.67 km/h. Correct answer: b. 76.67 km/h

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