## Thinking Mathematically (6th Edition)

$6$
The number of ways in which a series of successive things can occur is found by multiplying the number of ways in which each thing can occur. ---------- 1. The first leg (SF-NY) travel option can be chosen in 3 ways. 2. The second leg (NY-Paris) travel option can be chosen in 2 ways. Applying the Principle, the total number of choices is $3\times 2=6$