Question

Thirteen shaded and six unshaded hexagonal tiles were used to create the figure below. If a new figure is created by attaching a border of unshaded tiles with the same size and shape as the others, what will be the difference between the total number of unshaded tiles and the total number of shaded tiles in the new figure?

$5$

$7$

$11$

$12$

$18$

Solution:

The original figure has $13$ shaded tiles and $6$ unshaded tiles.

The new border is the next hexagonal ring around the figure, which has $18$ unshaded tiles.

The new figure has $6+18=24$ unshaded tiles and $13$ shaded tiles, so the difference is $24-13=11$ .

Thus, C is the correct answer.

2004 AMC 8 Problem 15

Solution:

Problem 15 in Other Years