| Date | May 2010 | Marks available | 2 | Reference code | 10M.1.sl.TZ1.13 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Find | Question number | 13 | Adapted from | N/A |
Question
In a research project on the relation between the gender of 150 science students at college and their degree subject, the following set of data is collected.
Find the probability that a student chosen at random is male.
Find the probability that a student chosen at random is either male or studies Chemistry.
Find the probability that a student chosen at random studies Physics, given that the student is male.
Markscheme
\( = \frac{{91}}{{150}}(0.607,{\text{ }}60.6\,\% ,{\text{ }}60.7\,\% )\) (A1)(A1) (C2)
Note: Award (A1) for numerator, (A1) for denominator.
[2 marks]
\( = \frac{{111}}{{150}}\left( {\frac{{37}}{{50}},{\text{ }}0.74,{\text{ }}74\,\% } \right)\) (A1)(ft)(A1) (C2)
Note: Award (A1)(ft) for their numerator in (a) +20 provided the final answer is not greater than 1. (A1) for denominator.
[2 marks]
\(\frac{{16}}{{91}}(0.176,{\text{ }}17.6\,\% )\) (A1)(A1)(ft) (C2)
Note: Award (A1) for numerator and (A1)(ft) for denominator. Follow through from their numerator in (a) provided answer is not greater than 1.
[2 marks]
Examiners report
Parts (a) and (b) were well answered with many candidates gaining 4 marks there. The conditional probability in part (c) proved to be more challenging. Nearly all candidates attempted this question showing that time was not a factor in this paper. Many candidates gave their answers as incorrectly rounded decimals, which incurred an accuracy penalty and prevented them from gaining the maximum marks.
Parts (a) and (b) were well answered with many candidates gaining 4 marks there. The conditional probability in part (c) proved to be more challenging. Nearly all candidates attempted this question showing that time was not a factor in this paper. Many candidates gave their answers as incorrectly rounded decimals, which incurred an accuracy penalty and prevented them from gaining the maximum marks.
Parts (a) and (b) were well answered with many candidates gaining 4 marks there. The conditional probability in part (c) proved to be more challenging. Nearly all candidates attempted this question showing that time was not a factor in this paper. Many candidates gave their answers as incorrectly rounded decimals, which incurred an accuracy penalty and prevented them from gaining the maximum marks.
