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

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 ).

- 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

Answer 3

- If x ≤ 150, the cost of the copies is C(x) = 9x [9 cents per copy for 150 copies or less].

- If 150 < x < 210, the cost of the copies is C(x) = 150(9) + 6(x - 150) [9 cents per copy for the first 150 copies, and 6 cents per copy for each additional copy over 150 but less than 210].
- If x ≥ 210, the cost of the copies is C(x) = 150(9) + 6(210 - 150) + 3(x - 210) [9 cents per copy for the first 150 copies, 6 cents per copy for the copies between 150 and 210, and 3 cents per copy for each copy 210 and above].