Puzzle of the Week for 14 December 1998: Hints
Most people find a puzzle such as this one much easier to solve with the
help of a picture.
Imagine that there is a camera high above the sidewalk,
taking pictures every few seconds that show where Jeremy and his family are.
If we cut off the sides of the pictures, leaving only the sidewalk, and
arrange the strips side-by-side, we might see something like the
picture above. The bakery is at the top of each strip, and the front
door of the toy store is at the bottom of each strip (but we cut them
off, so you can't see them). Jeremy is
represented by the yellow dot in each strip, and his family is the
cluster of red, green, and blue dots. The strips are in order from
left to right; the picture shows how Jeremy makes two round trips
between his family and the toy store. The yellow and blue lines
represent the paths of Jeremy and his family through space (up and
down in the picture) and time (increasing to the right in the
picture).
It may also be helpful to work through this problem backward.
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