When will the population density increase, under special conditions? When the number of :
- Deaths exceeds number of births and also number of emigrants equals number of immigrants.
- Births plus number of immigrants equals number of deaths plus number of emigrants.
- Births plus number of emigrants is more than the number of deaths plus number of immigrants.
- Births plus number of immigrants is more than the sum of number of deaths and number of emigrants.
Answer
(4) Births plus number of immigrants is more than the sum of number of deaths and number of emigrants.
Solution
Change in population density: Nt+1 = Nt + [(B + I) - (D + E)]
The density increases only when (B + I) > (D + E), i.e. births plus immigrants exceed deaths plus emigrants.
Answer: (4)