Answer:

Explanation:
See attachment for complete question.
We start by solving for the equation of the graph (The graph shows a linear equation)
Represent pencils with x and pen with y
From the graph, we have that:


Solve for slope (m)




The equation is calculated using:

Where







Add 4 to both sides


Now, to the question.
When pencils is 15 implies that

Solving for x, we have:





i.e. Pen = 10
Ratio = x ; y

Convert to fraction

Simplify

Hence,
