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Probability

Question
CBSEENMA9003375
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The length of a hall is 20 m and width 16 m. The sum of the areas of the floor and the flat roof is equal to the sum of the areas of the four walls. Find the height of the hall.

Solution

Let the height of the hall be h m.
Area of the floor = l x b
= 20 x 16 = 320 m2 Area of the flat roof = l x b
= 20 x 16 = 320 m2 Sum of the areas of the four walls = 2(l + b) h
= 2(20 + 16) h = 72 h m2 According to the question,
72 h = 320 + 320
rightwards double arrow space space space space space 72 straight h space equals space 640 space space space space rightwards double arrow space straight h equals 640 over 72 rightwards double arrow space space space space space straight h space equals space 80 over 9 space straight m
Hence, the height of the hall is 80 over 9 space straight m.

Some More Questions From Probability Chapter

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(i) Which box has the greater lateral surface area and by how much?

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(i)    What is the area of the glass?
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