Age Structure

A percentage tells us the share of children in the whole population, whereas the absolute number tells us how many children there actually are. These are related, but they are not the same measure. A falling share does not automatically mean that the number of children is falling. The total population must also be considered.

For example, if children form 30% of a population of 100 million, there are 30 million children. If their share falls to 25% but the total population rises to 140 million, there are 35 million children. Thus, the percentage declines while the absolute number increases. Therefore, option A correctly explains the situation. Options B and D confuse percentages with totals, and C is unrelated.

The old-age dependency ratio compares the number of older people with the working-age population. It is commonly expressed as older people divided by working-age people, multiplied by 100. The numerator in this situation remains constant, but the denominator becomes smaller. Dividing the same number by a smaller number produces a larger ratio.

Thus, each 100 working-age people would have to support or be compared with more older people than before, even though the absolute elderly population has not increased. Option B, “It will increase,” is therefore correct. It would decline only if the elderly population fell proportionately more, and it would remain unchanged only if both groups changed in a matching way.

Age structure shows how a population is divided among children, working-age people and older people. Retired people generally belong to the older age group, even though retirement age and personal circumstances can vary. If many retired people settle in a region, they add directly to the number of older residents. Unless an even larger group of younger people arrives at the same time, the elderly group will form a larger share of the regional population.

This does not mean that the child group becomes largest, that the working-age population doubles, or that fertility must rise. Migration of retired people mainly changes the composition by increasing the relative proportion of older persons. Therefore, option B is the most likely answer. The effect may also increase demand for health, housing and care services, but the central age-structure change is the larger elderly share.

The youth dependency ratio compares the population of children with the working-age population. It counts only the 0–14 age group as dependent for this measure; the elderly group is left out. The question gives 30% children and 60% people of working age, so these are the two figures needed for the calculation.

The ratio is \(30/60\times100=50\). This means that for every 100 working-age persons, there are 50 child dependents. Therefore, option B is correct. Adding the elderly 10% would produce a total dependency calculation, not a youth dependency ratio. The number 30 is also not correct because it is merely the child share of the whole population, not the comparison per 100 working-age persons.

Age structure shows how many people are present in different age groups. A large 40–59 group will gradually move into retirement and older ages. If the younger adult group aged 20–39 is unusually small, there may not be enough new workers to replace those who retire.

This imbalance can create pressure in two connected areas. Labour markets may face difficulty filling jobs, while pension and social-support systems may have to support more older people with a relatively smaller working-age base. The child population does not necessarily double, and people do not become young again. Therefore, future labour replacement and pension-support pressure is the logical result, making option A correct.

The total dependency ratio compares people in dependent age groups, commonly children and older persons, with people of working age. A low ratio means that the number of age-based dependents is relatively small compared with the working-age population. It does not tell us whether working-age people actually have jobs, earn enough, or can support household needs. Employment conditions, wages, prices, health costs, and family responsibilities also affect economic pressure.

Thus, option A is the most logical explanation. Many working-age adults may be unemployed, underemployed, or earning very little, so a numerically favourable age structure may still produce serious household hardship. Option B makes an unjustified assumption that low dependency guarantees high income. Option C ignores the costs of raising children and caring for older people, while option D incorrectly separates population structure from household economics. The ratio is useful but incomplete.

Children today form an important part of the future labour supply. After roughly 15 to 20 years, many of them will enter the working-age population and may seek jobs. Therefore, a country with a very small child population is likely to have a smaller group of new labour-market entrants when that cohort reaches adulthood. The exact result can be changed by migration, mortality and participation rates, but the demographic direction is clear.

The other choices are not supported. The working-age population cannot immediately double because children need time to grow up. Old-age dependency will not automatically disappear; in fact, a small younger generation may later have to support a relatively larger elderly group. A labour surplus in every sector is also not inevitable, since some sectors could face shortages. Thus, option A is the most likely effect.

The traditional old-age dependency ratio is usually calculated from age groups. It commonly compares people above a chosen old-age threshold with the working-age population and assumes that everyone in the older group is economically dependent. This is a convenient statistical measure, but it does not show each person’s actual work, income or health condition.

In the situation described, many people aged 65 and above are still employed, self-employed or otherwise earning income. They may contribute taxes and support themselves, so counting all of them as dependents exaggerates the real economic burden. The ratio is therefore useful for broad comparison but limited as a complete measure of dependency. It does not treat children as elderly, double-count the population or measure only births. Hence, option A is correct.

Population momentum means that population growth can continue after fertility has started to decline. If a country already has a very large young population, many of those young people will soon reach reproductive ages. Even when each woman has fewer children than earlier generations, the total number of women able to have children may remain large for some time.

Consequently, the number of births can stay high enough to exceed deaths, so the total population continues to grow before eventually stabilising or declining. Option A is correct because it refers to large cohorts moving into reproductive ages. The other options are biologically or demographically incorrect: lower fertility does not always raise mortality, elderly people do not become children, and age structure strongly affects total births.

The working-age population is the stated percentage of the whole population. To find a percentage of a total, multiply the total by the percentage written as a fraction of 100. This gives the number of people in the selected age group, not the percentage itself. The result can be expressed in both crore and million so that the units remain clear.

Here, 70 percent of 120 million is calculated as \(120\times70/100=84\) million. Since 1 crore equals 10 million, 84 million equals 8.4 crore. Therefore, option B is correct. A result such as 72 million would represent 60 percent, while 90 million would represent 75 percent, so those choices do not match the given 70 percent.

Very low fertility and a growing elderly population create several connected pressures. There may be greater demand for health care, pensions, long-term support, and suitable housing, while the future labour force may become smaller. A single action cannot address all these effects. A balanced policy therefore supports older people while also strengthening the economy and families.

Option B is correct because it combines elderly care, pension improvement, greater labour-force participation, skills, and family support. Better opportunities for women and older workers can increase participation, while education and training can raise productivity. Family support may make child-rearing easier, but simply promoting births is not enough. Closing schools or abolishing pensions would worsen social and economic problems rather than solve them.

The dependency ratio compares the population outside the working-age group with the working-age population. Children aged 0–14 and older people aged 65 and above are treated as dependents in this question. First find the working-age share by subtracting both dependent shares from the whole population. Then divide the dependent share by the working-age share and multiply by 100.

The dependent share is \(32+8=40\) percent. The working-age share is \(100-40=60\) percent. Therefore, the total dependency ratio is \(40/60\times100=66.67\), which rounds to 67 dependents per 100 working-age people. Thus option C is correct. Option A is only the dependent percentage, not the ratio relative to workers.

A percentage is a ratio: the number of elderly people divided by the total population. Consequently, the percentage can rise even when the elderly population itself falls, provided that the total population falls more rapidly. This is a comparison of two changing quantities, not a contradiction. The elderly group may shrink slightly while the whole population shrinks much more.

For example, suppose there are 20 elderly people in a population of 100, giving 20%. If the elderly number falls to 18 but the total population falls to 80, the new share is 22.5%. The absolute number has declined, but the percentage has increased. Rapid total-population growth would tend to lower the share, not produce the stated combination. Therefore, option A is correct. The other choices do not provide the necessary relationship between numerator and denominator.

A very large 10–19 age group will soon move through important transitions. Many will need secondary or higher education, vocational training, digital and practical skills, and later access to decent employment. If these needs are ignored, unemployment, underemployment, and wasted human potential may increase. Planning must begin before the cohort reaches working age.

Option B is correct because it prepares education systems, training institutions, and labour markets for this large group. Higher education alone may not suit everyone, so vocational pathways and job creation are also important. Old-age homes, pension taxes, and closing primary schools do not address the immediate needs of adolescents and young adults. The policy should help them become healthy, skilled, and economically productive.

Total output depends on more than the percentage of people in the working-age group. It also depends on how much each worker can produce, the quality of technology and capital, education and skills, organisation, and the number of people who actually participate in work. If these factors improve, each worker may produce more goods or services. As a result, total output can rise even when the working-age share of the population is falling.

Therefore, option A provides a valid explanation: productivity per worker may be increasing. For example, improved machines, training, infrastructure, or work methods can raise output per worker and offset a smaller working-age proportion. Option B is too narrow because population percentages alone do not determine production. Option C is an absolute and inaccurate claim, since some older people may remain economically active. Option D is also wrong because a lower share does not always force output to decline.

The three broad age groups together represent the entire population, so their percentages must add up to 100. The child group accounts for 38%, and the working-age group accounts for 57%. Their combined share is therefore 95%. The elderly share is whatever remains after these two groups are subtracted from the total.

The calculation is \(100-(38+57)=100-95=5\) percent. Hence, elderly people form 5% of the population, and option B is correct. This conclusion assumes that the three categories cover the whole population without overlap or an unlisted age group, which is the usual meaning of the age-structure data in the question. The other options do not satisfy the required total of 100%.

The old-age dependency ratio compares the number of older people with the working-age population. It is a relative measure, not a count of elderly people alone. The absolute number of older people can increase rapidly while the ratio remains almost unchanged if the working-age population also grows at a similar rate. In that situation, both the numerator and denominator rise together, so their relationship changes little.

Option A therefore gives the most likely explanation. For instance, migration, earlier population growth, or the movement of large cohorts into working ages could enlarge the working-age group alongside the elderly group. The ratio would not necessarily rise simply because the elderly count increased. Option B is impossible as a general explanation because children can exist even when elderly numbers rise. Options C and D use unsupported absolute claims. The important lesson is to distinguish population totals from ratios.

Children are the possible workforce of the future, but their number alone does not guarantee a demographic dividend. A dividend is more likely when children survive, grow well, learn effectively, and later find productive work. Poor nutrition can impair physical and cognitive development, while weak vaccination and health care can increase preventable illness and absence from school or work.

Therefore, poor childhood health may reduce the skills, productivity, and employability of the future labour force. Option A is correct. The benefit is not automatic merely because the child population is large; it depends on investment in health, nutrition, education, and jobs. The other choices describe effects that do not logically follow from poor vaccination and nutrition.

When total population remains unchanged, a change in an age group’s percentage directly changes its absolute number. Suppose the unchanged total population is \(N\). Initially, working-age people number \(0.62N\); later, they number \(0.69N\). Since \(0.69N>0.62N\), their actual number has increased.

The remaining population share falls from 38% to 31%, but this does not by itself identify whether children or elderly people increased. Nor can we conclude that total dependency must rise. The key information is the fixed total and the higher working-age share. Therefore, the absolute number of working-age people increased, so option A is correct.

Replacement-level fertility is the approximate fertility needed for each generation to replace itself, allowing for ordinary mortality. If fertility stays below that level for many decades, each new birth cohort tends to be smaller than the previous one. This gradually changes the shape of the age structure and reduces the relative size of younger groups.

As fewer children are born, the base of the age pyramid narrows and the population becomes older on average. Larger older cohorts also form a greater share of the total population as time passes. Therefore, option A—shrinking younger cohorts and increasing population ageing—is the most likely outcome. A continuously growing child population and a widening pyramid base contradict sustained below-replacement fertility; elderly people would not completely disappear.

Total dependency ratio has two components: youth dependency and old-age dependency. Both are calculated using the same working-age population as the denominator. Therefore, when the two component ratios are already given on that common basis, they can be added directly to obtain the total ratio.

Here, youth dependency is 60 and old-age dependency is 20. Thus, total dependency ratio = \(60+20=80\). This means that there are 80 dependents per 100 working-age persons, counting children and older people together. Therefore, option C is correct. The figures should not be averaged or multiplied; adding them is appropriate because the two groups are separate components of total dependency.

A high elderly share does not by itself determine how much the government spends on pensions. Public expenditure depends on the design and coverage of the pension system, eligibility rules, benefit levels and the sources of income used by older people. In some societies, older adults may receive support mainly from their own savings, employer pensions, assets or family members rather than from the government.

If many elderly people rely on these private or family arrangements, the government’s direct pension bill can remain relatively low even though the elderly proportion is high. This does not mean that ageing has no connection with social security; ageing can still increase pressure on families and public services. Nor are pensions always zero or support absent. Thus, option A gives a plausible explanation without claiming that all older people share the same situation.

The total dependency ratio usually compares all dependents—children and older people—with the working-age population. The old-age dependency ratio, however, uses only older people in the numerator and the working-age population in the denominator. Knowing that children form 28 percent of the total population does not reveal how many older people there are or, by itself, the exact size of the working-age group.

The total ratio of 75 combines child and old-age dependency. To separate the older component, the working-age population and either the child-dependent or elderly count must be known in compatible terms. Thus option A is the best answer. The other statements are false: total dependency is meaningful, child share can be useful, and old-age dependency is not determined only by birth rate.

Young women are often concentrated in both the working-age group and the reproductive-age group. When many of them migrate out of their region, the origin region may lose workers and also lose a substantial part of the population that could have had children there. This can reduce the number of births in later years, especially if returning migration or replacement migration is limited.

The result is not automatic in every case, because fertility behaviour, marriage patterns, migration of men and access to health services also matter. However, a fall in the number of women of reproductive age generally reduces the potential number of births. The elderly population cannot immediately double merely because young women leave, child mortality cannot become zero by necessity, and working-age men do not automatically increase. Therefore, option A is the most plausible demographic effect.

To find the change in the absolute number of elderly people, both the elderly share and the total population must be considered. A rise in the share from 10% to 15% is a relative change in composition, while a 20% rise in total population changes the number to which the share is applied.

Take the initial population as 100. Initially, elderly people number 10. After a 20% increase, the total population is 120. The new elderly number is \(15/100\times120=18\). The increase is from 10 to 18, or \(8/10\times100=80\%\). Therefore, option C is correct. The answer is not 50%, because that compares the shares alone and ignores total population growth.