The elevator in a eleven-storied office building travels at the rate of one floor per 1/4 minute, which allows time for picking up and letting down passengers. At the main floor and at the top floor the operator stops for 1 minute. How many complete (return) trips will the operator makes during a 7 hour period?
বিকল্পসমূহ (নিজের উত্তর যাচাই করতে ক্লিক করুন):
সঠিক উত্তর
1 (60)
বিস্তারিত ব্যাখ্যা ও বিশ্লেষণ:
Solution:
Complete trip = 10 floors up + 10 floors down
= 20 floors
Complete trip time taken
= 20 × (1/4) + 2 minutes
= 5 minutes + 2 minutes
= 7 minutes.
Now
7 hour = 7 × 60 minutes. = 420 minutes.
In 420 minutes operator can make = 420/7 = 60 trips.
