Five children — A, B, C, D, and E — are going to sit in five chairs in a row. Child D must be somewhere to the left of child E. How many possible configurations are there for the children?  Choose the correct answer:
A) 60 B) 180 C) 240 D) 360 E) 720
The number of ways to seat 5 people is 5! = 120.   Child D will sit to the left of Child E in exactly half of these arrangements.   The total number of possible arrangements is 120/2= 
<gadget id="calculator">120/2</gadget>
<output>60</output>
60   The answer is 60.
<result>A</result>
Five children — A, B, C, D, and E — are going to sit in five chairs in a row. Child D must be somewhere to the left of child E. How many possible configurations are there for the children?