Solution:
we are given that
The commission Gary earns is proportional to the cost of the shoes he sells.
Gary earns $15 in commission for every $150 worth of shoes that he sells.
we have been asked to find
Which equation gives the total commission, C, Gary will earn based on the cost, s, of the shoes he sells?
Since commission is $15 for a sells of $150.
So we can write
[tex] C=\frac{15}{150}*S\\\\\text{where S=Revenue from sell, C = Commission earned}\\ [/tex]
[tex] \Rightarrow C=\frac{1}{10}*S\\\\\Rightarrow C=\frac{S}{10}\\ [/tex] is the required equation.