MPSC 2021 Prelims Paper-I · Question 20 of 100

Correct — option (3), the order (d), (b), (f), (c), (a), (e): Monacco, Singapore, Baharain, Malta, Bangladesh, Mauritius, printing the paper's spellings for Monaco and Bahrain. The ranking these six occupy is stable, and the current published figures give exactly the same sequence: Monaco at about 19,400 people per square kilometre on an area of roughly two square kilometres, Singapore at about 8,300 on 737, Bahrain at about 2,000 on 790, Malta at about 1,700 on 320, Bangladesh at about 1,300 on 130,170, and Mauritius at about 640 on just under 2,000. The single most important thing this question tests is the difference between total population and population density. Bangladesh has by far the largest population of the six — over 160 million against Monaco's few tens of thousands — and three of the four answer choices begin with Bangladesh, which is not an accident. Density is population divided by area, and it is the divisor that decides the ranking here: Monaco is a city-state of two square kilometres, so even a small population produces an extraordinary figure, while Bangladesh spreads a very large population over 130,000 square kilometres and lands in fifth place. The pattern the sequence reveals is that the top of any density table is occupied by micro-states and city-states rather than by populous countries. Monaco and Singapore are entire countries that are effectively single urban areas; Bahrain and Malta are small island states, Bahrain's density having risen steeply with migrant labour drawn to the Gulf; Bangladesh is the densest of the world's genuinely large countries, which is why it appears in this list at all; and Mauritius, an island of about two thousand square kilometres with rather over a million people, is dense by world standards and yet the lowest of these six. Ordering questions of this kind are also decidable without exact figures — group the six into micro-states, small islands and large countries, then order within each group.

• (1)(a), (b), (f), (e), (c), (d) — This choice opens with Bangladesh and closes with Monaco, which is the ordering a candidate produces by ranking total population instead of density. It is the most complete inversion available in the option set: the country with the smallest area and the highest density is placed last, and the country with the largest area and the largest population is placed first. It also puts Mauritius above Malta, reversing a pair that is separated by a wide margin, since Malta's roughly 1,700 people per square kilometre is nearly three times Mauritius's 640. Any choice that begins with Bangladesh should be treated with suspicion on a density question, and here three of the four do.
• (2)(a), (d), (b), (c), (f), (e) — This choice again puts Bangladesh at the head, then arranges the rest into an order that is nearly right but not right: Monaco, Singapore, Malta, Bahrain, Mauritius. Even setting the opening error aside, it reverses Bahrain and Malta. That pair is the genuinely difficult one in this question, because both are small island or near-island states of comparable size and the gap between them is smaller than any other gap in the sequence. Bahrain sits above Malta at roughly 2,000 against roughly 1,700, its figure having climbed sharply with the migrant workforce that Gulf economies depend on, and that is the specific fact a candidate needs to separate the two.
• (4)(a), (b), (d), (e), (f), (c) — This is the third choice to begin with Bangladesh, and it then scatters the rest: Singapore, Monaco, Mauritius, Bahrain, Malta. It reverses the top pair by placing Singapore above Monaco, when Monaco's density is more than twice Singapore's, and it pushes Malta to the bottom, below Mauritius, when Malta is nearly three times as dense. The construction of this option set is worth noticing in itself: because three of the four choices open with the same country, the opening element carries almost no discriminating information, and a candidate must look at the second and third positions to make progress. On an ordering question always check where the choices actually differ before spending effort on where they agree.

Population density is the crudest of the measures of population distribution — arithmetic density, the total population divided by the total area — and its crudeness is what makes it both useful and misleading. It says nothing about how the population is distributed inside the territory, so a country that is mostly uninhabitable desert or mountain will show a low arithmetic density even where its habitable pockets are extremely crowded. Geographers therefore also use physiological density, population per unit of arable land, and agricultural density, farming population per unit of arable land, and the divergence between the three is often the interesting thing. Egypt is the standard illustration: a low arithmetic density across a territory that is almost entirely desert, and an enormous physiological density along the Nile. At the top of the world's arithmetic-density table sit territories that are effectively single cities — Macau, Monaco, Singapore, Hong Kong, Gibraltar — followed by small island states, and the highest-ranking large country is Bangladesh. India's own density at the 2011 census was 382 persons per square kilometre, with Bihar the densest state and Arunachal Pradesh the least dense.

MPSC includes world geography and demography alongside Indian material, and ordering questions are one of its favourite ways to test them, because an ordering question cannot be guessed from a single remembered fact. This one is unusual in printing six labelled items where most questions in the paper print four, and a candidate should register that before starting to match, since miscounting the items is an easy way to misread a choice. The reasoning skill being tested is the ability to separate two quantities that are constantly confused — how many people a country has and how crowded it is — and that confusion is exploited directly by making three of the four choices open with the most populous country in the list. The general technique for ordering questions is to sort into obvious tiers first and refine afterwards, and to look for the places where the answer choices actually diverge rather than working through each sequence from the beginning.

• Population density in this ordering sense is arithmetic density, total population divided by total area, and it is distinct from physiological density, which uses arable land, and from agricultural density, which uses the farming population.
• Current published figures for the six countries are Monaco about 19,400 per square kilometre on about two square kilometres, Singapore about 8,300 on 737, Bahrain about 2,000 on 790, Malta about 1,700 on 320, Bangladesh about 1,300 on 130,170 and Mauritius about 640 on just under 2,000.
• The top of any world density table is occupied by city-states and micro-territories such as Macau, Monaco, Singapore, Hong Kong and Gibraltar rather than by populous countries.
• Bangladesh is the densest of the world's large countries and is the only one of these six with a population in the hundreds of millions, which is precisely why it is the trap in this question.
• The English column prints Monacco with a double c and Baharain for Bahrain; both spellings are reproduced here exactly as printed and are not corrected.

• Ranking by total population when the question asks for density; three of the four choices here begin with Bangladesh precisely to catch that substitution
• Assuming the largest area implies the lowest density; among these six the country with the largest area is fifth of six, not last
• Reversing Bahrain and Malta, the closest pair in the sequence, where Bahrain's density has been raised well above Malta's by its migrant workforce
• Miscounting the items in a question that prints six labelled entries where most questions in the paper print four

Ordering questions appear in MPSC papers on population, area, length of rivers, height of peaks and volumes of production, and they are all attacked the same way: sort into tiers, place the extremes first, and then resolve the one or two adjacent pairs that are genuinely close. On demography specifically, the commission likes to test the distinction between an absolute quantity and a ratio — total population against density, total output against yield per hectare, total literates against the literacy rate — because that distinction separates candidates who have understood a measure from those who have memorised a list. Where the question dates itself, as this one does to 2012, check whether the ranking is stable over time before worrying about the exact year, since for most such lists it is.

No directly related past PYQ was found.

• practice — not a real PYQ

  Which of the following is the correct descending order of population density among these four countries ?

  • (a)Singapore, Bahrain, Bangladesh, Mauritius
  • (b)Bangladesh, Singapore, Bahrain, Mauritius
  • (c)Singapore, Bangladesh, Bahrain, Mauritius
  • (d)Bahrain, Singapore, Mauritius, Bangladesh

  Answer(a) Singapore, Bahrain, Bangladesh, Mauritius — the city-state comes first at roughly 8,300 people per square kilometre, then Bahrain at about 2,000, then Bangladesh at about 1,300 and Mauritius at about 640. The alternatives that place Bangladesh at or near the head substitute total population for density, which is the standard error this family of questions is built to expose.

• practice — not a real PYQ

  The measure obtained by dividing the total population of a country by its area of arable land, rather than by its total area, is known as which of the following ?

  • (a)Arithmetic density
  • (b)Agricultural density
  • (c)Physiological density
  • (d)Nutritional density

  Answer(c) Physiological density — population per unit of arable land, which reveals the pressure on cultivable ground that arithmetic density hides. Agricultural density divides only the farming population by arable land, and arithmetic density uses total area, which is the measure ordinary population-density tables report and the one used in ranking questions of this kind.