Step 1: Overview of Development Indicators
The development of a country is measured through various indicators, including economic, social, and health-related factors. These indicators help assess the overall well-being of a country's population.
Step 2: Why All the Factors Matter
- (A) Per capita income: Per capita income reflects the economic prosperity of a country and is often used to measure the standard of living.
- (B) Average literacy level: Literacy is an important social indicator, as it directly impacts the workforce's skills and overall development.
- (C) Health situation: A country's health situation is also crucial, as it influences productivity, life expectancy, and the quality of life.
Thus, the development of a country is determined by a combination of all these factors, making option (D) the correct answer.
Find the unknown frequency if 24 is the median of the following frequency distribution:
\[\begin{array}{|c|c|c|c|c|c|} \hline \text{Class-interval} & 0-10 & 10-20 & 20-30 & 30-40 & 40-50 \\ \hline \text{Frequency} & 5 & 25 & 25 & \text{$p$} & 7 \\ \hline \end{array}\]
Two concentric circles are of radii $8\ \text{cm}$ and $5\ \text{cm}$. Find the length of the chord of the larger circle which touches (is tangent to) the smaller circle.