If 9 persons can do 9 times of a particular work in 9 days, then, 7 persons can do 7 times of that work in?  Select:
A) 2 days B) 3 days C) 5 days D) 7 days E) 9 days
That is, 1 person can do one time of the work in 9 days.   Therefore, 7 persons can do 7 times work in the same 9 days itself.   9 days)
<result>E</result>
If 9 persons can do 9 times of a particular work in 9 days, then, 7 persons can do 7 times of that work in?