The population of a country doubles in 50 years. Assuming that the rate of increase of population is proportional to the number of inhabitants, in how many years would the population becomes three times ?

The population of city doubles in 80 years , in how many year will it be triple when the rate of increase is proportional to the number of inhabitants.

The population P in any year t is such that the rate of increase in the population is proportional to the population. Then

If the population of country double in 50 years, in how many years will it triple under the assumption that the rate of increase is proportional to the number of inhabitants.

If the population of country double in 50 years, in how many years will it triple under the assumption that the rate of increase is proportional to the number of inhabitants.

If the population of country double in 50 years, in how many years will it triple under the assumption that the rate of increase is proportional to the number of inhabitants.

If the population of country double in 50 years, in how many years will it triple under the assumption that the rate of increase is proportional to the number of inhabitants.

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.