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 2-hour period? Choose the correct choice from the following.
A) 88	B) 56	C) 42	D) 17	E) 64
Complete trip = 10 floors up and 10 floors down = 20 floors = 20*1/4= 
<gadget id="calculator">20*1/4</gadget>
<output>5</output>
5 minutes plus 2 minutes= 7 minutes.   2 hour = 120 minutes.   In 120 minutes operator can make 120/7=17 trips.   Answer: 17.
<result>D</result>
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 2-hour period?