One night 18 percent of the female officers on a police force were on duty. If 180 officers were on duty that night and half of these were female officers, how many female officers were on the police force? Choices:
A) 90 B) 180 C) 270 D) 500 E) 1,000
Let total number of female officers in the police force = F   Total number of officers on duty on that night = 180   Number of female officers on duty on that night = 180/2= 
<gadget id="calculator">180/2</gadget>
<output>90</output>
90   (18/100)*F= 90   =&gt;F = 500   Answer 500
<result>D</result>
One night 18 percent of the female officers on a police force were on duty. If 180 officers were on duty that night and half of these were female officers, how many female officers were on the police force?