The ratio between the areas of two pieces of lands is . If the area of land A exceeds that of land B by , find the area of land B.
We can use the concept of "the difference of parts" to solve this problem.
The ratio of land B's area to land A's area is , or . (We know that land B is associated with the first term of the ratio and land A with the second term because the area of land A exceeds the area of land B.) So, the area of land B = 1 part, and the area of land A = 13 parts.
The difference between the areas = 13 parts 1 part = 12 parts.
Since 12 parts = , then one part = .
The area of land B is 1 part, so its area = .