Answer:
100%
Step-by-step explanation:
Let the population in May = 2x
The population increases by 50 % which means that total become 150 % of the previous.
So, population in June =

The population increases by 50 % which means that total become 150 % of the previous.
So, population in July =

The population decreases by 11.11% which means that total become 88.89 % of the previous.
So, population in August =

Change in population from may to aug = 2x
This is 100% of the original.