SAT Probability and conditional probability Question

For a school competition, each student in the sixth, seventh, and eighth grades is assigned to either the red team or the green team. The table shows the distribution of grade and team for the students in the school. A student from the competition will be selected at random. What is the probability of selecting a student who is in the sixth or seventh grade, given that the student is on the green team? (Express your answer as a decimal or fraction, not as a percent.)