If the population of a country doubles in 60 years,in how many years will be triple(treble)under the assumption that the rate of increase is proportional in the number of inhabitants?given :`log 2=0.6312,log 3=1.0786`.

Find the population of a city at any time t,given that the rate of increase of population is proportional to the population at that instant and that in a period of 40 years the population increased 30,000 to 40,000.

The rate of growth of the population of a city at any time t is proportional to the size of the population. For a certain city it is found that the constant of proportionality is 0.04. Find the population of the city after 25 years if the initial population is 10,000. [take, e =2.7182] .

The population of a town increases at a rate proportional to the population at that time . If the population increases from 40 thousands to 60 thousands in 40 years, What will be the population in another 20 years ? = [ Given: sqrt(3/2) = 1.2247 ]

Use the given letters to write the answer: There are a trees in the village Lat. If the number of trees increases by b every year, how many trees will there be after x years?

The rate at which the population of a city increases varies as the population. In a perid of 40 years,the population increases from 4 lakhs to 6 lakhs. Show that in another 20 years,the population will be 7.348 lakhs (sqrt 3/sqrt 2=1.2247)

The rate of increase in the numbers of bacteria culture is proportional to the number present.If initially there were 1000 bacteria and the number doubles in 1 hour,find the number of bacteria after a time of 2 1/2 hours.