Grades 7-8 Video Solutions 2021-video 2021 7-8/22

Video Transcription

Video Summary

The problem involves determining the label on a hidden cannonball in a triangular pyramid formed by 20 cannonballs, marked with labels A, B, C, D, or E. Each label is used four times across the visible cannonballs on three pyramid faces. By recreating and analyzing the pyramid's layout when flattened into a net, and accounting for overlapping labels when folded back into the pyramid, it is revealed that the visible cannonballs are A, B, C, 3 D’s, and 4 E’s. Therefore, the hidden cannonball on the fourth face must be labeled D to complete the set of four D-labeled balls.

Keywords

cannonball

triangular pyramid

labels

hidden

puzzle