In a dance hall, the ratio of the number of men who are dancing to the number of women who are dancing is 2:3. If there are 30 men dancing, how many women are dancing in the hall?
If the ratio of the number of men who are dancing to the number of women who are dancing is 2:3, then the total ratio representing the number of people dancing in the hall is 2+3 =5
Since there are 30 men dancing, the number of women dancing in the hall is 3/2*30 = <<3/2*30=45>>45. Answer: \boxed{45}.