Date | May 2014 | Marks available | 6 | Reference code | 14M.1.sl.TZ1.5 |
Level | SL only | Paper | 1 | Time zone | TZ1 |
Command term | Find | Question number | 5 | Adapted from | N/A |
Question
Celeste wishes to hire a taxicab from a company which has a large number of taxicabs.
The taxicabs are randomly assigned by the company.
The probability that a taxicab is yellow is 0.4.
The probability that a taxicab is a Fiat is 0.3.
The probability that a taxicab is yellow or a Fiat is 0.6.
Find the probability that the taxicab hired by Celeste is not a yellow Fiat.
Markscheme
recognize need for intersection of Y and F (R1)
eg \({\text{P}}(Y \cap F){\text{, }}0.3 \times 0.4\)
valid approach to find \({\text{P}}(Y \cap F)\) (M1)
eg \({\text{P}}(Y) + {\text{P}}(F) - {\text{P}}(Y \cup F)\), Venn diagram
correct working (may be seen in Venn diagram) (A1)
eg \(0.4 + 0.3 - 0.6\)
\({\text{P}}(Y \cap F) = 0.1\) A1
recognize need for complement of \(Y \cap F\) (M1)
eg \(1 - {\text{P}}(Y \cap F){\text{, }}1 - 0.1\)
\({\text{P}}\left( {(Y \cap F)'} \right) = 0.9\) A1 N3
[6 marks]