**Question:** The population of community X has 30% below 15 years of age and 10% over 65 years of age. Dependency ratio of community X is

A. (30% x 2) / (100% - (30% + 10%))
B. (30% x 2) / (100% - 30% - 10%)
C. (30% x 2) / (100% - 40%)
D. (30% x 2) / (100% - 30% - 10%)

**Core Concept:** Dependency Ratio is a demographic statistic that measures the number of dependents (youth and elderly) relative to the working-age population (15-64 years).

**Why the Correct Answer is Right:** The correct formula for calculating dependency ratio is derived from dividing the number of dependents by the number of working-age population. In this case, we have two age groups as dependents: children (below 15 years) and elderly (above 65 years). We can simplify the calculation as follows:

A. (30% x 2) / (100% - (30% + 10%))
B. (30% x 2) / (100% - 30% - 10%)
C. (30% x 2) / (100% - 40%)
D. (30% x 2) / (100% - 30% - 10%)

**Why Each Wrong Option is Incorrect:**

A. The correct calculation involves subtracting the proportions of the dependent groups (children and elderly) from the total population (100%). Option A incorrectly assumes that we need to add the proportions of children and elderly instead of subtracting.

B. Option B has a minor arithmetic error. The correct calculation involves subtracting the proportions of dependent groups (children and elderly) from the total population (100%). Option B incorrectly subtracts the proportions of children and elderly from the total population (100%).

C. Option C incorrectly subtracts the proportions of children and elderly from the total population (100%).

D. Option D has a similar arithmetic error to Option B. The correct calculation involves subtracting the proportions of dependent groups (children and elderly) from the total population (100%). Option D incorrectly subtracts the proportions of children and elderly from the total population (100%).

**Core Concept Explained:**

The Dependency Ratio is a demographic statistic that measures the number of dependents (children and elderly) relative to the working-age population (15-64 years). In this scenario, there are 30% children and 10% elderly, leaving a working-age population of 60%. A high dependency ratio indicates a smaller working-age population relative to the dependent population, which can lead to economic challenges for the community.

**Why Each W