Life is A Test 2: Test Harder (Quite A Bit Harder)

by Brony_of_Brody

The Answer 20

There are 10,946 different paths that you could take.

There's only one way to "reach" Stepping Stone 0: stay exactly where you are. There's also only one way to get to Stepping Stone 1: by advancing one space.

When it comes to Stepping Stone 2, you can get there two ways: one stone at a time, or advance two spaces at once. As for Stepping Stone 3, you could advance once three times, advance one then two spaces, or two then one space.

More generally, the total ways you can reach a stepping stone is equal to the combined total ways you can reach the two stepping stones previously. This is because you can advance one or two stones at a time, so one of the two stones behind it must have been your starting point. So starting on the shore, we can see the number of ways to reach the stepping stones in sequence is 1, 1, 2, 3, 5, 8, 13...

These numbers are known as Fibonacci numbers (for the nerdier readers among you). And the twentieth Fibonacci number is our solution - 10,946.