For a population of 10000, sex ratio of more than 1000 means
In the given question

Total population is 10,000.
Also, Ideal sex ratio implies 5000 females for 5000 males
So, Sex ratio is more than 1000, it implies, Females are more than 1000 per 1000 males
Thus, females are > 5000 and males are < 5000
Males are less than 500
Females are less than 500
Females are less than 5000
Males are less than 5000