A population of snails has an annual per capita birth rate o

A population of snails has an annual per capita birth rate of 0.055 and an annual per capita death rate of 0.015. Calculate an estimate of the change in population size over one year, for a given starting population of 1,000 individuals. Assume that the population grows exponentially according to the equation

Solution

Here Birth rate (b) =0.055

Death rate (d) =0.015

Hence rate (r) =b-d =0.055- 0.015 = 0.040

Time is one year hence t= 1

Initial population is 1000 i.e. N= 1000

dN/dt= rN equation rearragned dN= dt x rN

dN= 1 x 0.040 x1000 =40

Hence the population will increase by 40 individuals

First Option is correct