Question 8
An open-ended tube holds at most three balls. Adding a fourth pushes a ball out of the opposite end, as shown in both examples.
Starting with the pictured tube, the beaver performs the four insertions from left to right in the displayed instruction sequence; each arrow tells the direction of insertion.
Which picture shows the final tube?
Starting with the pictured tube, the beaver performs the four insertions from left to right in the displayed instruction sequence; each arrow tells the direction of insertion.
Which picture shows the final tube?