Someone please help me with this

In the question it gives you the equation n = [tex]\frac{10}{3}t[/tex]
I assume that "t" represents time
Since it asks you for 7 hrs you plug 7 in the place of "t" :
[tex]n = \frac{10}{3}(7)[/tex]
This can also be written as:
[tex]n = \frac{10}{3}(\frac{7}{1})[/tex]
so...
n = [tex]\frac{70}{3}[/tex]
Which can be converted into decimal form of:
23.33333
This means that Olivia will sell about 23 boxes in 7 hr
Hope this helped!