Study the graph and answer the following questions:

How many more persons are there in the age group of $10-19$ years than in the age group of $30-39$ years?

Study the graph and answer the following questions:

What is the age group of the persons whose populations is exactly $1200?$

Study the graph and answer the following questions:

What is the total number of persons living in the town in the age group of $50-59$ years?