Question

A school has three gates and four staircases from the first floor to the second floor. How many ways does a student have to go from outside the school to his classroom on the second floor?

Answer 1

A student can go inside the school from outside in 3 ways and from the first floor to the second floor in 4 ways.
∴ Number of ways to choose gates = 3
Number of ways to choose staircase = 4
By using the fundamental principle of multiplication, the number of ways in which a student has to go from outside the school to his classroom = 4 × 3 = 12