Final answer:
To determine the number of blocks needed for the first course of a 40ft long wall, divide the length of the wall by the length of one block. Assuming a standard block size is 1.33 ft long, approximately 30 blocks would be required.
Step-by-step explanation:
To calculate the number of blocks needed for the first course of a wall that is 40ft long, you would first need the standard size of the block being used. Since this information is not provided, we cannot compute the exact number of blocks required.
Assuming a standard concrete block size which is typically 16 inches long (1.33 ft) and 8 inches high (0.67 ft), you would divide the total length of the wall by the length of one block.
Therefore, if the wall is 40 ft long, you would divide 40 ft by 1.33 ft (the length of one block) to find out how many blocks you need to cover the entire length of the wall:
40 ft / 1.33 ft per block ≈ 30 blocks
Since we are only calculating for the first course, we only need one layer of blocks, so approximately 30 blocks would be required for the first course of the wall.