1. The cost C (in dollars) per unit of making x photocopies at The Office Shop is given below. • 18 cents for at most 20 copies
• 12 cents for more than 20 copies up to 50
• 9 cents for more than 50 copies but less than 100
• 5 cents for 100 copies or more but up to 200
• 3 cents for more than 200 copies

Part A: Write the piecewise-defined function that represents the situation.
Part B: Explain why it would not be cost-effective to make 150 photocopies