| Date | May 2009 | Marks available | 4 | Reference code | 09M.2.hl.TZ2.1 |
| Level | HL only | Paper | 2 | Time zone | TZ2 |
| Command term | Find | Question number | 1 | Adapted from | N/A |
Question
In a class of \(20\) students, \(12\) study Biology, \(15\) study History and \(2\) students study neither Biology nor History.
(a) Illustrate this information on a Venn diagram.
(b) Find the probability that a randomly selected student from this class is studying both Biology and History.
(c) Given that a randomly selected student studies Biology, find the probability that this student also studies History.
Markscheme
(a)
A1A1
Note: Award A1 for a diagram with two intersecting regions and at least the value of the intersection.
(b) \(\frac{9}{{20}}\) A1
(c) \(\frac{9}{{12}}\left( { = \frac{3}{4}} \right)\) A1
[4 marks]
Examiners report
Although this was the best done question on the paper, it was disappointing that a significant number of candidates produced Venn diagrams with key information missing.
