Question

    The perimeter of a square field is 16 cm more than the

    perimeter of a rectangle. The length of the rectangle is 72 cm which is 300% of its width. If a street of width 10 cm surrounds from outside the square, then find the total cost of constructing the street at the rate of Rs. 20 per sq. cm?
    A Rs. 66,560 Correct Answer Incorrect Answer
    B Rs. 60,000 Correct Answer Incorrect Answer
    C Rs. 49,600 Correct Answer Incorrect Answer
    D Rs. 37,600 Correct Answer Incorrect Answer

    Solution

    Let the width of the rectangle = x cm Then, 300% of x = 72 x = 72 × 100/300 = 24 cm Perimeter of the rectangle = 2(length + width) = 2 × (72 + 24) = 192 cm Perimeter of the square = (192 + 16) = 208 cm The sides of the square = 208/4 = 52 cm The area of the square field without street = (52)2 sq. cm = 2704 sq. cm  The area of the square field with street = (52 + 20)2 sq. cm = 5184 sq. cm The area of the street = 5184 – 2704 = 2480 sq. cm The total cost of constructing the street = 2480 × 20 = Rs. 49,600  

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