Population Growth

Correct answer: A. High mortality can offset a large part of additions from births

Population growth is determined by births and deaths together, not by the birth rate alone. A high birth rate adds people, but a very high infant mortality rate removes many of those additions through deaths at an early age. Other deaths may also reduce the natural increase. Therefore, the final growth can be small even when births are numerous, depending on the size of the death rate and migration.

Option A is correct because high mortality can offset a substantial part of the increase produced by births. Option B is false: birth rate is directly related to population change. Option C confuses mortality with migration, which is the movement of people. Option D is too absolute; a high birth rate does not always produce negative growth. The proper conclusion requires considering both births and deaths.

Correct answer: A. High natural increase

During this interval, mortality falls before fertility falls. That means fewer people are dying, while births remain high for several years. The difference between births and deaths therefore becomes large and positive. This difference is called natural increase, so population growth from natural causes is expected to be high. Migration is not needed to explain this stage.

Option A is correct: high natural increase. The situation does not imply negative or zero growth, because births still exceed deaths. It is also not migration-only growth, since the question describes a strong natural difference. This pattern is commonly associated with an early or expanding phase of demographic transition, although the exact size of growth depends on the actual birth and death rates.

Correct answer: A. Their demographic dynamics and age structures may differ

Zero total growth means that the final population is unchanged overall, but it does not reveal how many births and deaths occurred on the way. A country with high births and high deaths may have rapid population turnover, while one with low births and low deaths may have much less movement between age groups. Their age structures, health conditions, life expectancy, and future growth potential can therefore differ.

Thus choice A is correct: their demographic dynamics and age structures may differ. For example, equal high births and deaths can support a relatively young population and greater instability, whereas low births and deaths may be associated with an older, more stable population. Equal totals do not mean equal processes. Births and deaths remain important even when their net effect is zero.

Correct answer: C. More than 35 years

The Rule of 70 is an approximate method for estimating doubling time when the annual growth rate remains fairly constant. At a 2 percent rate, it gives approximately \(70\div2=35\) years. This estimate assumes that the rate does not change during the period. If the rate gradually falls, the population will add people more slowly than the constant-rate estimate assumes.

Because growth becomes slower over time, the population will need more than 35 years to double. Therefore, option C is correct. The doubling time would not become zero or necessarily remain exactly 35 years. The rule is useful for a stable approximate rate, but it must be interpreted cautiously when the rate changes.

Correct answer: A. Employment, rental housing, and transport

People aged 20 to 35 are generally in the working-age group. When many such migrants arrive, the city must first support their immediate needs: employment, affordable or rental housing, transport, and access to everyday urban services. These needs arise directly from the age and mobility profile described in the question. Later, family formation may also increase demand for schools and healthcare.

Thus, option A is the best answer. The question asks about the near future, so jobs, rental housing, and transportation are more directly connected than elderly homes or agricultural land. Primary-school demand might rise later if migrants bring or have children, but it is not the most immediate or certain consequence. The conclusion concerns likely service demand, not a guaranteed outcome for every migrant.

Correct answer: A. School demand may remain high while the local labor force weakens

Births increase the number of children, while the migration of young adults removes people who are usually in the working-age group. These two processes can happen at the same time and produce different effects on public services and employment. A rural region may therefore continue to need schools for many children even as farms, businesses, and local services lose working-age residents.

Option A is correct: school demand may remain high because the child population is large, while the local labour force may weaken because young adults leave. The word “may” is important because exact outcomes depend on birth levels, the scale of migration, and the age of those remaining. The other choices are too absolute or incorrectly claim that out-migration has no structural effect.

Correct answer: C. 0 percent

Total population growth combines natural increase with net migration. Natural increase contributes plus 1 percent. Net out-migration means that more people leave than enter, so its contribution is negative 1 percent. The two effects must therefore be added with their signs: \(1+(-1)=0\) percent.

Thus the total growth rate is 0 percent, making option C correct. This means the total number of people can remain approximately stable during the period, even though many births, deaths, arrivals, and departures may still occur. A positive natural increase does not by itself guarantee total growth when an equal negative migration balance offsets it.

Correct answer: A. A stable total population can hide major changes in age structure

A total population is the sum of all age groups, so a stable total does not mean that the age structure is unchanged. In this case, the working-age group is becoming smaller while the elderly group is becoming larger. These changes can affect the number of available workers, the tax base, demand for health care, and the need for pensions and support, even if the total number of people remains constant.

Therefore option A is the most appropriate conclusion. Option B is wrong because the composition of the population is changing. Option C is wrong because age structure can have important economic effects. Option D is also wrong: growth in the elderly group is part of the total population’s changing composition. A total figure can hide major internal demographic changes.

Correct answer: B. It may increase

Food availability per person depends on the ratio of total food production to total population. To compare the new situation with the old one, production is multiplied by 1.08 and population by 1.05. The new per-person availability is therefore multiplied by \(1.08/1.05\), which is greater than 1. This means each person has more food available on average, assuming other conditions stay unchanged.

Since 8 percent production growth is greater than 5 percent population growth, food production grows faster than the number of people sharing it. Numerically, \(1.08/1.05\approx1.0286\), or about a 2.86 percent rise in per-person availability. Therefore option B is correct. The increase is not necessarily 8 percent, but it is likely positive; it will not be zero or an unavoidable decline.

Correct answer: A. Pressure on per-capita water capacity will increase

Water-supply capacity is a resource limit, while population determines how many people may need that resource. Here population rises by 10%, but capacity rises by only 2%. Therefore the number of people grows much faster than the available supply. If ordinary consumption patterns remain broadly similar, the capacity available for each person will come under greater pressure.

The comparison is also clear numerically: if the initial population is 100 and capacity is 100 units, the new population is 110 but capacity is only 102 units. Capacity per person falls from 1 unit to about \(102\div110\), or 0.93 unit. Thus option A is the most likely outcome. The question does not claim that actual supply must fall, only that per-person capacity faces greater pressure.

Correct answer: A. Large cohorts born earlier are now entering working ages

A population is made up of age cohorts that move forward through life over time. The current growth rate describes the overall change now, but it does not make every age group shrink immediately. Earlier periods of high birth numbers can create a large group that is only later reaching working ages.

As that large cohort enters the working-age range, the working-age population can increase even while fertility and the overall growth rate decline. Therefore, option A is correct. A falling growth rate does not mean all groups instantly fall, and working-age population is directly related to the age structure of the total population.

Correct answer: B. Births, deaths, migration, age structure, growth rates, and their change over time

A complete study of population growth must examine both the sources of change and the structure that shapes future change. Births and deaths determine natural increase, while migration changes the population of particular places. Age structure shows how many people may soon enter working or reproductive ages. Growth rates and their changes over time reveal whether the process is accelerating, slowing, or reversing.

Therefore option B is correct. Total population and land area are useful for size and density, but they cannot explain growth by themselves. Birth and death rates alone omit migration and age composition. Migration and density alone omit natural increase. The broad combination in B provides a more complete demographic picture and allows present changes to be connected with future population momentum.

Correct answer: C. 21 percent

Percentage growth must be calculated relative to the initial population, not the final population. The initial population is 40 million and the final population is 48.4 million. The absolute increase is \(48.4-40=8.4\) million. Dividing this increase by the initial 40 million and multiplying by 100 gives \(\frac{8.4}{40}\times100=21\) percent.

Therefore, option C, 21 percent, is correct. The same calculation can be written with whole numbers as \(\frac{48,400,000-40,000,000}{40,000,000}\times100=21\%\). The units cancel because both populations are measured in millions. A common error is to compare the increase with the final population or to treat the difference of 8.4 million as a percentage without dividing by the starting value. Growth percentages conventionally use the starting population as the base.

Correct answer: A. Increase of 1500

Total population change has two main components: natural change and net migration. Natural change equals births minus deaths. Net migration equals in-migrants minus out-migrants. The overall change is the sum of these two components, so people entering and leaving must both be included rather than using births and deaths alone.

Natural increase is \(7200-5100=2100\). Net migration is \(1600-2200=-600\), because 600 more people leave than enter. The total change is therefore \(2100+(-600)=1500\), an increase of 1500 people. Hence option A is correct. The value 2100 ignores the population loss through migration.

Correct answer: A. 13 per thousand

Total population growth combines natural increase and net migration. Natural increase is calculated as the birth rate minus the death rate. Net migration is then added, keeping its sign: a negative rate means that out-migration is greater than in-migration. Ignoring that negative contribution would overstate the final growth rate.

Natural increase is \(29-7=22\) per thousand. Adding net migration gives \(22+(-9)=13\) per thousand. Therefore, the total growth rate is 13 per thousand and option A is correct. The value 22 per thousand is only the natural increase; it is not the total because migration reduces the population by 9 per thousand.

Correct answer: A. Decrease of 0.2 million

Total population change equals natural increase plus net migration. Births add people, deaths remove people, and net out-migration also removes people. The figures are in millions, so they can be combined directly after using the appropriate signs.

Natural increase is \(1.8 - 1.1 = 0.7\) million. Net out-migration of 0.9 million is a loss, so total change is \(0.7 - 0.9 = -0.2\) million. Thus, the population decreases by 0.2 million, or 2 lakh people. Therefore, option A is correct. The positive natural increase is smaller than the migration loss.

Correct answer: B. Final population is 132 percent of initial population

A 32 percent increase means the final population is the original population plus 32 percent of the original. Therefore final population = 100 percent + 32 percent = 132 percent of the initial population. This conclusion does not require knowing how the increase was distributed across the eight years.

If the initial population is \(P\), the final population is \(P + 0.32P = 1.32P\), or 132 percent of \(P\). Hence option B is definitely correct. The data do not prove that growth was exactly 4 percent every year; equal annual growth would involve compound calculation and is not stated. They also do not reveal the birth rate or migration level, so options C and D cannot be concluded.

Correct answer: A. A lower rate on a large population base can still add many people

Percentage growth and absolute growth are different ideas. The percentage rate tells us what fraction of the existing population is added, while absolute growth tells us the actual number of people added. When the starting population is very large, even a relatively small percentage can represent a large number of people.

For example, a 1.4 percent increase applied to 100 million people adds 1.4 million people in one year. Thus a fall from 2.8 percent to 1.4 percent does not mean that additions immediately become small; it means the rate is lower relative to a large base. The base population may remain large for years. Therefore option A is correct; the other choices are not necessary explanations.

Correct answer: A. A large population is present in reproductive ages

Fertility rate and the total number of births are related but not identical. Fertility rate describes the average number of children per woman, while total births also depend on how many women are in the reproductive-age group. A country may have lower fertility but still contain a very large generation born during an earlier high-fertility period.

When that large generation reaches reproductive ages, many women may have children even if each woman has fewer children on average. This creates population momentum and keeps the total number of births high for some time. Therefore option A is correct. Death rate, land area, and migration do not directly explain this specific delay in falling births.

Correct answer: C. +3 per thousand

Total growth rate is obtained by combining natural change with net migration. Natural change equals the birth rate minus the death rate. Here it is \(18-24=-6\) per thousand, meaning a natural decrease of six people per thousand.

Net migration is positive nine per thousand, so it is added to the natural change: \(-6+9=+3\) per thousand. Therefore option C is correct. Although deaths exceed births, enough people enter through migration to produce a small overall increase. The answer is not +9 because that would ignore natural change.

Correct answer: B. -8 per thousand

The relationship between the rates is total growth = natural increase + net migration. To find net migration, subtract natural increase from total growth. Because the total growth is smaller than the natural increase here, the result must be negative. This indicates that more people are leaving than entering.

Using the values, net migration is \(6-14=-8\) per thousand. The negative 8 per thousand reduces the natural increase of 14 to a total growth of 6 per thousand. A positive 8 would increase the total to 22, not 6. Therefore, the correct choice is option B, negative 8 per thousand.

Correct answer: C. 21 percent

Total percentage growth compares the absolute increase with the original population. The starting population is 2 million and the final population is 2.42 million. First find the numerical increase: \(2.42-2.00=0.42\) million, or 420,000 people.

Now compare this increase with the original 2 million: \(\frac{0.42}{2.00}\times100=21\%\). Therefore option C is correct. The five-year period does not change the requested total percentage; it would matter only if the question asked for an annual growth rate. The final value 2.42 million itself is 121% of the initial value, so the increase is 21%, not 24.2%.

Correct answer: C. 1.331 million

A constant annual percentage increase produces compound growth, not simple growth. In compound growth, the increase earned during one year becomes part of the population on which the next year's increase is calculated. Thus, a population growing at 10 percent is multiplied by 1.10 each year. For three consecutive years, the multiplier is applied three times.

Final population = 1,000,000 × 1.10 × 1.10 × 1.10 = 1,331,000. In lakh notation, this is 13.31 lakh, so option C is correct. Simply adding 10 percent three times would give 1.3 million and ignore the extra growth on earlier increases. The result is approximately 1.331 million because the question asks for an approximate population, while the stated calculation gives the exact value under the constant-rate assumption.

Correct answer: A. No change

Successive percentage changes are applied to the changing population, so they should be calculated one after another rather than simply adding or subtracting the percentages. Take an initial population of 100 as a convenient example. A 25 percent increase multiplies it by 1.25. A 20 percent decline then multiplies the new value by 0.80.

The final value is \(100\times1.25\times0.80=100\). The first increase produces 125, and 20 percent of 125 is 25; subtracting 25 returns the population to 100. Therefore, there is no final change and option A is correct. The two percentages cancel here because the second percentage is applied to the larger intermediate value.

Correct answer: A. From 20 to 15 per thousand

Natural increase rate is calculated by subtracting the death rate from the birth rate. Both rates are given per thousand, so the subtraction can be done directly and the answer remains per thousand. It is important not to add the two rates, because births increase population while deaths reduce it.

Initially, the natural increase is \(32-12=20\) per thousand. After the changes, it is \(24-9=15\) per thousand. Therefore, the natural increase falls from 20 to 15 per thousand, a decrease of 5 per thousand. Option A is correct. Although both birth and death rates decline, the birth rate falls by more, so natural increase becomes smaller.