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प्रश्न
A multistorey building has 25 floors above the ground level each of height 5 m. It also has 3 floors in the basement each of height 5 m. A lift in building moves at a rate of 1 m/s. If a man starts from 50 m above the ground, how long will it take him to reach at 2nd floor of basement?
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उत्तर
Man covers the distance above the ground = 50 m
And man covers the distance below the ground = 2 × 5 = 10 m ...[∵ Distance between two floors = 5 m]
Thus, total distance = 50 m + 10 m = 60 m

∵ Speed of the lift = 1 m/s ...[Given]
Hence, time taken to reach second floor of basement = `"Distance"/"Speed"`
= `(60 m)/(1 m//s)`
= 60 s or 1 min
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