A hint to get started
Multiply the choices for two successive road stages
There are 2 roads connecting City A and City B, and 3 roads connecting City B and City C. There is no direct road that links City A to City C. How many ways are there to travel from City A to City C?
CJC · Lecture · Example 2
Decide whether order matters and repetition is allowed; then count stages or disjoint cases.