Question

    The sides of a triangle are in the ratio 5:7:12, and its

    perimeter is 144 cm. What is the difference in length between the longest and the shortest side?
    A 28 cm Correct Answer Incorrect Answer
    B 30 cm Correct Answer Incorrect Answer
    C 42 cm Correct Answer Incorrect Answer
    D 56 cm Correct Answer Incorrect Answer

    Solution

    Let the length of sides of triangle be '5a' cm, '7a' cm and '12a' cm.

    Perimeter of triangle = sum of the length of each sides of triangle

    5a + 7a + 12a = 144

    Or, 24a = 144

    So, 'a' = 6 cm

    So, largest side = 12a = 12 X 6 = 72 cm

    And, smallest side = 5a = 5 X 6 = 30 cm

    Required difference = 72 - 30 = 42 cm

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