Which of the following country's population does not have triangular shaped age-sex pyramid?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → Australia
An age-sex pyramid shows how many males and females there are in each age group. A triangular pyramid has a wide base: many children, because the birth rate is high. A bell-shaped pyramid tapers towards the top: birth and death rates are almost equal.
Option (1) Australia — Does not have a triangular pyramid. Its pyramid is bell shaped and tapered towards the top, which shows a near constant population.
Option (2) Bangladesh — Has a triangular pyramid. Its pyramid looks the same as that of Nigeria, with a wide base.
Option (3) Nigeria — Has a triangular pyramid. It is the example of an expanding population, typical of less developed countries.
Option (4) Mexico — Has a triangular pyramid. Its pyramid also looks like that of Nigeria, with a large population in the lower age groups.
Note: This question is taken from the pre-rationalised NCERT book. The latest edition (2026-27) does not have this part. An extract of the pre-rationalised NCERT book is given below for the benefit of students.
Pre-rationalised NCERT: “Expanding Populations … The age-sex pyramid of Nigeria as you can see is a triangular shaped pyramid with a wide base and is typical of less developed countries. These have larger populations in lower age groups due to high birth rates. If you construct the pyramids for Bangladesh and Mexico, it would look the same.” “Constant Population … Australia’s age-sex pyramid is bell shaped and tapered towards the top. This shows birth and death rates are almost equal leading to a near constant population.” |