Draw a tree diagram representing the possible outcomes, clearly labelling each branch with the correct probability.

Find the probability that Tim and Caz eat the same type of chocolate.

     A1A1A1

[3 marks]

Note: Award A1 for the initial level probabilities, A1 for each of the second level branch probabilities.

$\frac{{10}}{{16}} \times \frac{9}{{15}} + \frac{6}{{16}} \times \frac{5}{{15}}$     (M1)

$= \frac{{120}}{{240}}{\text{ }}\left( { = \frac{1}{2}} \right)$     A1

[2 marks]

Generally well done. A few candidates didn’t take account of the fact that Caz ate the chocolate, so didn’t replace it. A few candidates made arithmetic errors in calculating the probability.

Generally well done. A few candidates didn’t take account of the fact that Caz ate the chocolate, so didn’t replace it. A few candidates made arithmetic errors in calculating the probability.