Question

A biologist studied the population of rats in a barn, He found that the average natality was 250, average mortality 240, immigration 20 and emigration 30. The net increase in population is :

• A. 10
• B. 15
• C. 5
• D. zero

Answer 1

The correct option is D zero

Natality = 250, Immigration = 20
Mortality = 240, Emigration = 30
Increase in Popolution size
P.D = [(Natality+Immigration)-(Mortality+Emigration)]
= [(250 + 20 - (240 + 30)]
= 0