Question

In the city where Aiko lives, there are 44 buses that go from point AA to point BB, 33 buses that go from point BB to point CC, and 55 buses that go from point CC to point DD. How many different ways can Aiko use the buses to travel from AA to BB to CC to DD? There are __[blank]__ different ways that Aiko can use the buses to get from AA to BB to CC to DD. Enter your

Answer 1

60

Explanation:

For each of the 4 buses from A to B, Aiko can take 3 possible routes to C, for a total of 4×3 = 12 ways to get from A to C.

Then, for each of those, Aiko can take any of 5 buses to D, for a total of 12×5 = 60 different ways Aiko can use buses to get from A to D.