Answer:
[tex]x=3*\dfrac{b}{150}[/tex]
Step-by-step explanation:
Let x = number of books that Hannah donated
We know that the number of students is 150 and the total number of books is represented by b, we can write that as:
Average number of books donated by each student = [tex]\dfrac{b}{150}[/tex]
Now we know that Hannah donated 3 times as much as the average. We can write that as:
[tex]x=3*\dfrac{b}{150}[/tex]
