If the birth rate of a population is higher than the death rate and the immigration and emigration rates remain the same the population size increase or decrease

The size of the population will increase.

According to the situation, If 100 is the birth rate and 10 is the death rate. immigration and emigration rate are both 5.Then the population will increase by 90 individual every year. It means if the population is 400 this year, next year it will be 490.