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प्रश्न
A rectangular examination hall having seats for 500 candidates has to be built so as to allow 4 cubic metres of air and 0.5 square metres of floor area per candidate. If the length of hall be 25 m, find the height and breadth of the hall.
उत्तर
Total number of seats in rectangular examination hall = 500
Length of the hall = 25 m
Cubic metres of air for per candidate = 4 m3
Square metres of floor area for per candidate = 0.5 m2
∴ Height of the hall = `"Volume of air per candidate"/"Square metre of floor area for one candidate"`
= `4/0.5`
= `40/5`
= 8 m
Total capacity of the hall = 500 × 4 = 2000 m3
∴ Breadth of the hall = `200/(25 xx 8) = 80/8` = 10 m
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Solution :
The surface area of the sphere = 4πr2
= `4 xx 22/7 xx square^2`
= `4 xx 22/7 xx square`
= `square xx 7`
∴ The surface area of the sphere = `square` sq.cm.
