Prime DSE Series - Mathematics Mock Exam Papers (Extended Part) Module 1 Set 3

HKDSE-MATH-EP(M1)(Set 3) − 4 4 © United Prime Educational Publishing (HK) Ltd. Answers written in the margins will not be marked. Answers written in the margins will not be marked. Answers written in the margins will not be marked. 3. A factory produces chocolate bars of 3 brands, X , Y and Z in the ratio 1 : 3 : 5. A quality check is carried out and it is found that 0.6% of brand X , 0.4% of brand Y and 0.2% of brand Z chocolate bars produced are contaminated. (a) Find the probability that a randomly selected chocolate bar is brand Y and it is not contaminated. (b) Find the probability that a randomly selected chocolate bar is not contaminated. (c) Given that a chocolate bar is contaminated, find the probability that the chocolate bar is brand Y . (6 marks) Sample © United Prime Educational Publishing (HK) Limited All rights reserved; no part of this publication may be reproduced, photocopied, recorded or otherwise, without the prior written permission of the Publisher.