Question

the country a has 50m inhabitants, and its population grows 3% per year. the country b, 70m and grows 2% per year. tell in how many years a will surpass b. in cpp

Answer 1

Country A:

Growth Rate = 50m(1 + 3/100)ⁿ

Growth Rate = 50m(1.03)ⁿ

Country B:

Growth Rate = 70m(1 + 2/100)ⁿ

Growth Rate = 70m(1.02)ⁿ

Find n when Country A surpass Country B:

50m(1.03)ⁿ = 70m(1.02)ⁿ

1.03ⁿ ÷ 1.02ⁿ = 70m ÷ 50m

(103/102)ⁿ = 1.4

n log (103/102) = log (1.4)

n = log (1.4) ÷  log (103/102)

n = 34.5 years ≈ 35 years

Answer: Country A will surpass Country B in 35 years