Pattern blocks increase by 2 blocks per image. If the first image has 4 blocks, how many blocks are in the 5th image?

• A. 9 blocks
• B. 12 blocks
• C. 10 blocks
• D. 8 blocks

Answer: (B)

Pattern blocks grow by a fixed amount each image, so the sequence is arithmetic. Here, each step adds 2 blocks, starting with 4 blocks in the first image. To reach the fifth image, there are four steps from the first image, and each step adds 2 blocks. So the total increase is 4 × 2 = 8 blocks. Add that to the starting 4: 4 + 8 = 12. The fifth image has 12 blocks.