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    Question

    The length, breadth and height of a room are in the

    ratio 2:3:4. If the breadth and height are halved while the length is doubled, then the total area of the four walls of the room will
    A Remains the same Correct Answer Incorrect Answer
    B will decreases by 43.75% Correct Answer Incorrect Answer
    C willl decreases by 31.25% Correct Answer Incorrect Answer
    D will decreases by 45% Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    Let length = 2, breadth = 3 & Height of room = 4 So original total area of four walls = 2(2 x 4 + 3 x 4) = 2(8 + 12) = 2 x 20 = 40 Then new length = 4, new breadth = 1.5 and new height = 2 So new total area of four walls = 2(4 x 2 + 1.5 x 2) = 2(8 + 3) = 2 x 11 = 22 ; Hence decrease in total area of four walls = (40 - 22)/40 x 100 = 45%

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