In a class of 98 students, all play at least one of the three games — snooker, chess and tennis. 42 students play snooker, 49 play tennis, and 43 play chess. The total number of students who play any and only two games is 29. 5 students play all the three games. The number of students who play only snooker and only chess is equal. 11 students play only snooker and tennis. 6 students play only snooker and chess. How many students play only tennis?