A coach recorded timer choices from three practice groups. The two-way frequency table is summarized as follows: Group 1: phone timer 25, wall clock 16, online timer 17; Group 2: phone timer 25, wall clock 19, online timer 23; Group 3: phone timer 16, wall clock 22, online timer 20. If one student is selected at random from all students in the table, what is the probability that exactly one of these is true: the student is in the Group 2 group; the student selected wall clock?