Final answer:
The net displacement of the delivery truck is 15 blocks east and 6 blocks south.
Step-by-step explanation:
To find the net displacement of the delivery truck, we can add the individual displacements in the x and y directions. Starting from the origin, the truck travels 21 blocks north, which corresponds to a positive displacement of 21 blocks in the y-direction. Next, it travels 15 blocks east, which corresponds to a positive displacement of 15 blocks in the x-direction. Finally, it travels 27 blocks south, which corresponds to a negative displacement of 27 blocks in the y-direction.
To calculate the net displacement, we add the displacements in the x and y directions separately. In the x-direction, the truck has a displacement of 15 blocks east and no displacement in the y-direction. Therefore, the net displacement in the x-direction is 15 blocks east. In the y-direction, the truck has a displacement of 21 blocks north and a displacement of 27 blocks south. To calculate the net displacement, we subtract the magnitude of the displacement in the y-direction that is opposite in direction. So, the net displacement in the y-direction is 21 blocks - 27 blocks = -6 blocks south.
Therefore, the net displacement of the truck from its starting point is 15 blocks east and 6 blocks south, which corresponds to option C) 6 blocks south.