Track / Stage 4 / 100 of 340 #360 of 1964

Problem 360

AMC 12 late, AIME early

Combinatorics Difficulty 4.8 Multiple choice

In the diagram, how many $1 \times 1$ squares are shaded in the $8 \times 8$ grid?

Pick one

Official solution

In the diagram, there are 7 rows in which there are shaded squares, and there are 7 shaded squares in each row.

Thus, there are $7 \cdot 7=49$ shaded squares.

ANswer: (E)

Source: NuminaMath-1.5, licensed Apache-2.0. Statement and solution reproduced as published; topic, difficulty and ordering added by this site.