A local photocopying store advertises as follows. " We charge 9 cents per copy for 150 copies or less, 6 cents per copy for each copy over 150 but less than 210 , and 3 cents per copy for each copy 210 and above. " Let x be the number of copies ordered and C(x) be the cost of the job (in cents ).

Question

- If x \leq 150, the cost of the copies is C(x) =
- If 150 < x < 210, the cost of the copies is C(x) =
- If x \geq 210, the cost of the copies is C(x) =

Answer 1

C(x)
= 9x for x <= 150
= 9*150+6(x-150) for 150 < x < 210
= 9*150 + 6*59 + 3(x-210) for x >= 210

Answer 2

C(x)
= 9x for x <= 150
= 9*150+6(x-150) for 150 < x < 210
= 9*150 + 6*59 + 3(x-209) for x >= 210