2 < x < 15;
a) x = 3, 2 < 3 < 15,
x = 5, 2 < 5 < 15,
x = 7, 2 < 7 < 15,
x = 11, 2 < 11 < 15,
x = 13, 2 < 13 < 15,
б) x = 4, 2 < 4 < 15,
x = 6, 2 < 6 < 15,
x = 8, 2 < 8 < 15,
x = 10, 2 < 10 < 15,
x = 12, 2 < 12 < 15,
x = 14, 2 < 14 < 15;
Ответ: а) 3, 5, 7, 11, 13.
б) 4, 6, 8, 10, 12, 14.