A farmer wants to plant trees at the outside boundaries of his rectangular field with dimensions 650 meters 780 meters. Each tree requires 5 meters of free space all around it from the stem. How much free area will be left?
Correct Answer: A
Rationale: To calculate the area taken by the trees, we need to account for the space each tree requires. Each tree needs 5 meters of free space all around it, totaling 10 meters added to each dimension. Therefore, the new dimensions of the field are (650-10) meters by (780-10) meters. Calculating the area of the new field: (640m 770m = 492,800m²). To find the free area remaining, subtract the new field's area from the original field's area: 507,000m² - 492,800m² = 14,200m². Therefore, the free area left after planting the trees is 14,200m². Choice A is the correct answer as it represents the free area left after planting the trees.