Sex ratio means
(a) Number of males/1000 females
(b) Number of females/1000 males
(c) Both A and B
(d) None of the above

Hint: Sex ratio is the attribute of a population. An individual can either be male or female. It is a ratio of males to females in a population. A measure of population is indicated by these attributes like sex ratio, population density, etc. The ratio indicates how many times the observed number contains another number.

Complete answer:
Sex ratio means the number of females/1000 males. This ratio gives the number of females in 1000 males. This ratio tends to be 1:1. Deviations have been observed in this trend very often. It is given by pattern by age- higher at a very young age, the gap narrows with increasing age and goes below 100 by middle age.

Additional Information: - Sex ratio varies from one population to another. It is better to consider separately sex ratios of different races or by ethnicity.
- This information regarding sex ratio is an important social indicator to measure the extent of equality between males and females in a society at a given time.
- The sex ratio in the country with regard to females has always remained unfavorable.
- Female foeticide is still very prevalent and this is a matter of concern.
- In the population census of 2011 it was revealed that the population ratio in India is 940 females per 1000 of males. It shows an upward trend from 2001 data. 2001 population census shows 933 females to that of 1000 males.
So, the correct answer is the `number of females/1000 males`.

Note: Although many states have a sex ratio of less than one some states like Kerala have a sex ratio of 1058 females every 1000 males, Puducherry has a sex ratio of 1001 females every 1000 males. Whereas Delhi has a sex ratio of 821 females every 1000 males and Haryana has a sex ratio of 861. Thus, it shows the grim scenario regarding female foeticide in India.