In a certain math department, students are required to enroll in either Calculus or Trigonometry, each of which is offered in beginner and advanced courses. The number of students enrolled in Trigonometry is 50% greater than the number of students enrolled in Calculus, and 70% of Calculus students are enrolled in the beginner course. If 4/5 of students are in the beginner courses, and one student is selected at random, what is the probability that an advanced Trigonometry student is selected?
Select the correct option
A) 8%  B) 16%  C) 20%  D) 24%  E) 40%
Let x be the number of students in calculus.   Then the number of students in trigonometry is 1.5x   The number of students on beginner calculus is 0.7x   The number of students in beginner trigonometry is 4/5*(2.5x) - 0.7x = 1.3x   The number of students in advanced trigonometry is 0.2x   The percentage in advanced trigonometry is 0.2x / 2.5x  4/5*(2.5 ) - 0.7= 
<gadget id="calculator"> 4/5*(2.5 ) - 0.7</gadget>
<output>1.3</output>
1.3x   The number of students in advanced trigonometry is 0.2x   The percentage in advanced trigonometry is 0.2x / 2.5x= 8%   The answer is 8%.
<result>A</result>
In a certain math department, students are required to enroll in either Calculus or Trigonometry, each of which is offered in beginner and advanced courses. The number of students enrolled in Trigonometry is 50% greater than the number of students enrolled in Calculus, and 70% of Calculus students are enrolled in the beginner course. If 4/5 of students are in the beginner courses, and one student is selected at random, what is the probability that an advanced Trigonometry student is selected?