| Date | May 2009 | Marks available | 3 | Reference code | 09M.1.sl.TZ2.2 |
| Level | SL only | Paper | 1 | Time zone | TZ2 |
| Command term | Calculate | Question number | 2 | Adapted from | N/A |
Question
A plumber in Australia charges 90 AUD per hour for work, plus a fixed cost. His total charge is represented by the cost function C = 60 + 90t, where t is in hours.
Write down the fixed cost.
It takes \(3 \frac{1}{2}\) hours to complete a job for Paula. Find the total cost.
Steve received a bill for 510 AUD. Calculate the time it took the plumber to complete the job.
Markscheme
AUD 60 (A1) (C1)
[1 mark]
C = 60 + 90(3.5) = AUD 375 (M1)(A1) (C2)
Note: Award (M1) for correct substitution of 3.5.
[2 marks]
Note: Unit penalty (UP) applies in this part
510 = 60 + 90t (M1)(A1)
(UP) t = 5h (hours, hrs) (A1) (C3)
Note: Award (M1) for setting formula = to any number.
(A1) for 510 seen.
[3 marks]
Examiners report
The majority of candidates answered this question correctly. Some gave an answer of 150 AUD.
The majority of candidates answered this question correctly.
The majority of candidates answered this question correctly. Very few lost a unit penalty mark in this part.
