Identify the unit rate in the graph.
a) $5
b) $10
c) $15

d) $20

Easy,

write the coordinates out in pairs:

x= hours
y= earnings

(1,10)
(2,20)
(3,30)
(4,40)
(5,50)

Now it makes it much easier to see the increase,

After 1 hour of working she has made $10
After 2 hours of working she has made $20
After 3 hours of working she has made $30

And so on,

that being said it's easily seen that she is getting paid $10

Thus the unit rate is $10.