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2021 AMC 12D Question 17

AMC12 · 2021 AMC 12D

Question 17

A bug starts at a vertex of a grid made of equilateral triangles of side length $1.$ At each step the bug moves in one of the $6$ possible directions along the grid lines randomly and independently with equal probability. What is the probability that after $5$ moves the bug never will have been more than $1$ unit away from the starting position?
  1. $\dfrac{13}{108}$
  2. $\dfrac{7}{54}$
  3. $\dfrac{29}{216}$
  4. $\dfrac{4}{27}$
  5. $\dfrac{1}{16}$