In a graduating class, 40 percent of the students are male. In this class, 40 percent of the male students and 30 percent of the female students are 25 years old or older. If one student in the class is randomly selected, approximately what is the probability that he or she will be less than 25 years old?  Choose the correct option.
A) 0.66 B) 0.72 C) 0.78 D) 0.84 E) 0.9

Rationale: "let x be the total number of students . the number students who are younger than 25 is 0.6 * 0.4 x + 0.7 * 0.6 x = 0.66 x the answer is a ."
Answer: A