Question

question 2: if precision industries needs to have a cleanings, what is the least expensive plan?
least expensive plan for a:
question 3: if precision industries needs to have b cleanings, what is the least expensive plan?

Explanation:

Step1: Compare costs at point A

At number of cleanings = A, the dashed blue line has a lower cost than the solid black line and dotted red line.

Step2: Compare costs at point B

At number of cleanings = B, the dotted red line has a lower cost than the solid black line and dashed blue line.

Answer:

Least expensive plan for A: The plan represented by the dashed blue line
Least expensive plan for B: The plan represented by the dotted red line