Question

An ant starts at (0, 0), and only makes moves of length 1 in the positive x directions or the positive y direction. How many paths are there from the ant that end at (3, 3) but never pass through (2, 3)

Answer 1

The number of paths that are there from the ant that end at (3, 3) but never pass through (2, 3) is 4.

Explanation:

The possible pathways are as follows:

(0, 0) → (1, 0) → (2, 0) → (3, 0) → (3, 1) → (3, 2) → (3, 3)

(0, 0) → (1, 0) → (2, 0) → (2, 1) → (2, 2) → (3, 2) → (3, 3)

(0, 0) → (1, 0) → (1, 1) → (1, 2) → (2, 2) → (3, 2) → (3, 3)

(0, 0) → (0, 1) → (0, 2) → (1, 2) → (2, 2) → (3, 2) → (3, 3)

Thus, the number of paths that are there from the ant that end at (3, 3) but never pass through (2, 3) is 4.