Consider the following graphs. The curves in the graphs indicate different age groups in the populations of two countries A and B over a period of few decades: With reference to the above graphs, which of the following are the most logical and rational inferences that can be made? 1. Over the last two and a half decades, the dependency ratio for country B has decreased. 2. By the end of next two and a half decades, the dependency ratio of country A will be much less than that of country B. 3. In the next two decades, the work-force relative to its total population will increase in country B as compared to country A. Select the correct answer using the code given below.

UPSC CSAT 2018 Q71: Consider the following graphs. The curves in the graphs indicate different age groups in the… — Answer & Explanation

CSAT 2018 · Q71

Consider the following graphs. The curves in the graphs indicate different age groups in the populations of two countries A and B over a period of few decades:

With reference to the above graphs, which of the following are the most logical and rational inferences that can be made?

1.Over the last two and a half decades, the dependency ratio for country B has decreased.
2.By the end of next two and a half decades, the dependency ratio of country A will be much less than that of country B.
3.In the next two decades, the work-force relative to its total population will increase in country B as compared to country A.

Two line graphs, 1950–2050, of population (in millions) by age group (<15, 15–64, 64+). Country A: 15–64 rises to about 1.0 by 2010 and falls to about 0.87 by 2050; <15 drifts down from about 0.33 to 0.22; 64+ climbs past the <15 line around 2030 to about 0.34. Country B: 15–64 keeps rising to about 1.1 by 2050; <15 stays around 0.3–0.36; 64+ rises slowly to about 0.26. — From UPSC's question paper.

Select the correct answer using the code given below.

Answer & explanation

Answer: (c) 1 and 3 only

Dependency ratio = (under-15 + over-64) ÷ working-age (15–64). In B the working-age group grew much faster than the dependants over the past 25 years, so the ratio fell (1). Ahead, A's working-age group shrinks while its elderly grow, so A's ratio will not be much lower than B's (2 fails), and B's working-age share rises while A's falls (3).

Dependency ratio = (<15 + 64+) ÷ (15–64).
Country B, about 1990: (0.32 + 0.05) ÷ 0.54 ≈ 0.69; about 2015: (0.36 + 0.11) ÷ 0.84 ≈ 0.56 — decreased.
Around 2043: A ≈ (0.23 + 0.31) ÷ 0.92 ≈ 0.59; B ≈ (0.32 + 0.22) ÷ 1.07 ≈ 0.50 — A's ratio is higher, not much lower.
Working-age share, about 2018 → 2038: B ≈ 0.65 → 0.67 (up); A ≈ 0.68 → 0.65 (down).

✓ 1. In B the 15–64 group grows from about 0.54 to 0.84 million over the period while dependants rise only from about 0.37 to 0.47, so the ratio falls.
✗ 2. By the early 2040s A's elderly have overtaken its children and its working-age group is shrinking; its ratio (about 0.59) is above B's (about 0.50).
✓ 3. B's working-age group keeps growing faster than its dependants, while A's working-age group declines and its elderly grow.

Remember · Dependency ratio = (children + elderly) ÷ working-age; read all three curves at both dates before judging the direction.

Question and answer: UPSC's official GS Paper II (2018, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 1 Oct 2026 (how we verify). ·

Consider the following graphs. The curves in the graphs indicate different age groups in the…

CSAT 2018 · Q71

More on Data interpretation & sufficiency