In a certain company, the ratio of the number of males to females is 5:3. If 30 more males join the company, the new ratio becomes 2:1. How many females are currently in the company?
Correct: C
Let's denote the number of males as 5x and the number of females as 3x. When 30 more males join, the number of males becomes 5x + 30, and the ratio changes to (5x + 30) / 3x = 2 / 1. Solving this equation gives us 5x + 30 = 6x, so x = 30. The current number of females is 3x = 3 * 30 / 5 * 3 = 18.