Question

Suppose a certain religious university has a ratio of approximately 90 males to 125 females enrolled as a students. If he current enrollment at the university is 15000 and every male on campus asks a female student to a dance, how many women will be without dates to the dance?

Answer 1

How many males and how many females would there be if the total enrollment is 15000?

Ratio is 

  90 males      15000 - x
  ------------- = ---------------
   125 fem              x

Then 90x = 1875000 - 125x, or 215x = 1875000

                                                      x = approx 8720 females
                       and 15000-8720, or 6279 males

If every male finds a dance partner, that would leave (8720-6279) females, or 2440, without dance partners.  ;(

Check:  is the male:female ratio near 90:125?

Is 6279:8720 approx equal to 90:125?

Yes.  0.72 (approx) = 0.72 (approx).