In a survey, some people were asked which of three types of tea, labelled X, Y and Z, they preferred. The diagram shows part of a pie chart that illustrates the results. The angle of the sector that represents the people who preferred Y is 168°. [Figure 13]

1. (a)Complete the pie chart.[1]
2. (b)Find the fraction of people who preferred Y. Express your answer in its simplest form.[1]
3. (c)Given that 80 people preferred X, calculate the number of people in the survey.[1]

This question uses a diagram from the original paper, which isn't shown here. Open the full paper from the past papers archive to see it.