The elevator in an eleven-story office building travels at the rate of one floor per 1/4 minute, which allows time for picking up and discharging passengers. At the main floor and at the top floor, the operator stops for 1 minute. How many complete trips will an operator make during a 7-hour period?
A) 88
B) 56
C) 42
D) 60
E) 64
OA IS D. pls assist
elevator
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FOR the first complete trip time taken=10/4+1+10/4=6 minpappueshwar wrote:The elevator in an eleven-story office building travels at the rate of one floor per 1/4 minute, which allows time for picking up and discharging passengers. At the main floor and at the top floor, the operator stops for 1 minute. How many complete trips will an operator make during a 7-hour period?
A) 88
B) 56
C) 42
D) 60
E) 64
OA IS D. pls assist
for second trip= 1+10/4+10/4+1=7 min
for third=7 and so on
let there be x no of 7 min trips,
then
6+7x=7*60
x=59.14
hence total complete trips of 7 min= 59
hence total trips = 7 min trips+6 min trip=59+1=60
hence D
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10 floors are passed on the way up (floors 2-11), and 10 floors passed on the way down (floors 10-1).pappueshwar wrote:The elevator in an eleven-story office building travels at the rate of one floor per 1/4 minute, which allows time for picking up and discharging passengers. At the main floor and at the top floor, the operator stops for 1 minute. How many complete trips will an operator make during a 7-hour period?
A) 88
B) 56
C) 42
D) 60
E) 64
OA IS D. pls assist
Thus, 1 complete trip = 20 floors.
At a rate of 1/4 minute per floor, the time for 20 floors = 20/4 = 5 minutes.
Since there is a 1-minute stop at the top and a 1-minute stop at the bottom, the total time per trip = 5+1+1 = 7 minutes.
In 7 hours -- which is 420 minutes -- the number of trips = 420/7 = 60.
The correct answer is D.
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We are given that an elevator takes 1/4 minute to travel between floors and that it stops for one minute at the top floor and also on the main floor. Since the elevator is traveling from the main floor to the 11th floor, it's traveling 10 total floors.pappueshwar wrote:The elevator in an eleven-story office building travels at the rate of one floor per 1/4 minute, which allows time for picking up and discharging passengers. At the main floor and at the top floor, the operator stops for 1 minute. How many complete trips will an operator make during a 7-hour period?
A) 88
B) 56
C) 42
D) 60
E) 64
Thus, the total time it takes for the elevator to go from the bottom floor to the 11th floor and back down is:
20 x 1/4 = 5 minutes
Since the elevator stops for a minute each at the top and main floors, the amount of time to complete a trip is:
5 + 2 = 7 minutes = 7/60 hours
Thus, in 7 hours the elevator can complete 7/(7/60) = 60 trips.
Answer: D
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