| Date | May 2009 | Marks available | 2 | Reference code | 09M.1.sl.TZ1.11 |
| Level | SL only | Paper | 1 | Time zone | TZ1 |
| Command term | Find | Question number | 11 | Adapted from | N/A |
Question
A fair six-sided die has the numbers 1, 2, 3, 4, 5, 6 written on its faces. A fair four-sided die has the numbers 1, 2, 3, and 4 written on its faces. The two dice are rolled.
The following diagram shows the possible outcomes.
Find the probability that the two dice show the same number.
Find the probability that the difference between the two numbers shown on the dice is 1.
Find the probability that the number shown on the four-sided die is greater than the number shown on the six-sided die, given that the difference between the two numbers is 1.
Markscheme
\(\frac{4}{{24}}\) \(\left( {\frac{1}{6},0.167,16.7{\text{ }}\% } \right)\) (A1)(A1) (C2)
Note: Award (A1) for numerator, (A1) for denominator.
[2 marks]
\(\frac{{7}}{{24}}\) \((0.292,29.2{\text{ }}\% )\) (A1)(A1)(ft) (C2)
Note: Award (A1)(ft) from the denominator used in (a).
[2 marks]
\(\frac{{3}}{{7}}\) \((0.429,42.9{\text{ }}\% )\) (A1)(A1)(ft) (C2)
Note: Award (A1) for numerator (A1)(ft) for denominator, (ft) from their numerator in (b).
[2 marks]
Examiners report
The diagram caused some difficulty for some candidates, however the majority of candidates were successful.
The diagram caused some difficulty for some candidates, however the majority of candidates were successful in (a).
The term “difference” was well understood by the candidature.
The diagram caused some difficulty for some candidates, however the majority of candidates were successful in (a).
