6 :)
no. of books: 1 2 3 4
combinations: 12, 13, 14, 23, 24, and 34
Answer:
idk refrace your question
Step-by-step explanation:
3 pairs of choices give rise to 2^3 = 8 possibilities:
.. bus, full, morning
.. bus, full, afternoon
.. bus, concession, morning
.. bus, concession, afternoon
.. train, full, morning
.. train, full, afternoon
.. train, concession, morning
.. train, concession, afternoon