Final answer:
To minimize the amount of wire used, the worker should position the stake approximately 26.67 meters from the base of the 12-meter pole.
Step-by-step explanation:
To find the position of the stake that minimizes the amount of wire used, we can use the concept of similar triangles. The ratio of the height of the shorter pole (12 meters) to the distance of the stake from the base of the shorter pole is equal to the ratio of the height of the taller pole (30 meters) to the distance of the stake from the base of the taller pole. Let's call the distance of the stake from the base of the shorter pole x. Using this information, we can set up the following equation:
(x + 40) / x = 30 / 12
Cross-multiplying and solving for x, we get:
12x + 480 = 30x
480 = 18x
x = 26.67 meters
Therefore, the worker should position the stake approximately 26.67 meters from the base of the 12-meter pole to use the least amount of wire.