Math Problem Solver

During the five year period from 2018 to 2022, the populations of Countries A, B, and C showed

consistent growth. The total population of the three countries in 2018 was 100 million whereas in 2021

and 2022 it was 20% and 30% more than that in 2018. The ratio of the populations of countries B and

C in 2022 was 4 : 3.

Country A: In 2018 the population was 50 million. In 2019 and 2021 the population was respectively

4% and 12% more than that in 2018 whereas the population in 2020 was the average of that in the

years immediately before and after it. The ratio of the population in 2018 and 2022 respectively was 5

: 6.

Country B: In 2018 the population was 60% that of Country A. It increased by 10% in 2019 with

respect to the previous year whereas the increase in numbers in 2020 was the same as that in 2019.

Country C: In 2019 the population increased by 10% with respect to the previous year. In 2021 the

population of C was half that of A in the same year. In the year 2020, the ratio of the populations of B

and C was 3 : 2 respectively