Question

    A was travelling from point X to point Y. He increased

    his speed by 20 km/h after every hour. He reached his destination in 14 hours. If his initial speed was 60 km/h, then what was his average speed in the whole journey?
    A 100 km/h Correct Answer Incorrect Answer
    B 140 km/h Correct Answer Incorrect Answer
    C 190 km/h Correct Answer Incorrect Answer
    D 150 km/h Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Total distance travelled by A = (14/2) × {2 × 60 + (14 – 1) × 20} = 10 × (120 + 260) = 2660 km Required average speed = 2660/14 = 190 km/h

    Practice Next