Answer:
The total number of volunteers working more than 15 hours are 60.
Step-by-step explanation:
From the histogram, we see that,
The range of volunteers working more than 15 hours are given by,
When the number of hours worked are between 16-20 and 21-25.
<em>So, the number corresponding to these ranges will given the number of volunteers working more than 15 hours.</em>
Thus, we have,
The number of volunteers working between 16-20 hours are 50.
The number of volunteers working between 21-25 hours are 10.
Hence, the total number of volunteers working more than 15 hours = 50+10 = 60.