Question

The histogram represents ages of 40 people at a store that sells children's clothes.
walve anoitaupa geivio?
12
11+
10
9
8
7
6
S
4
3
2
1
0
0 5 10 15
20 25 30 35
age (years)
How many people at the store were at least 10, but less than 20 years old