Suppose that a magnet high school includes grades 11 and 12, with half of the students in each grade. 30% of the senior class and 40% of the junior class are taking calculus. Suppose a calculus...

Suppose that a magnet high school includes grades 11 and 12, with half of the students in each grade. 30% of the senior class and 40% of the junior class are taking calculus. Suppose a calculus student is randomly selected to accompany the math teachers to a conference. What is the probability that the student is a junior? (Enter your answer as a fraction.)