To find the total number of people who visited the amusement park and were between 0 and 20 years old, we need to add the number of people in the age groups represented in the first two bins of the histogram:
- Number of people between 0 and 10 years old: 700 people
- Number of people between 10 and 20 years old: 200 people
Now, we add these two values together:
700 + 200 = 900
Therefore, there were 900 people who visited the amusement park who were between 0 and 20 years old.