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2 marksConditional Probability

CSEC Additional Mathematics · 2017 · Paper 2 · Question 7(c)(ii)

A school cafeteria sells 20 chicken patties, 10 lentil patties, and 25 saltfish patties daily. On a particular day, a student ordered 2 patties without specifying the type, and the vendor randomly selected 2 patties.

Given that the first patty was saltfish, calculate the probability that the second patty was NOT saltfish.

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Other parts of this question

  1. 7(a)(i)Draw a tree diagram to illustrate the information above.[4 marks]
  2. 7(a)(ii)Determine the probability that the student will be accepted for an internship programme.[4 marks]
  3. 7(b)(i)Determine the mean length.[2 marks]
  4. 7(b)(ii)Determine the modal length.[1 mark]
  5. 7(b)(iii)Determine the median length.[1 mark]
  6. 7(b)(iv)Determine the interquartile range for the data.[2 marks]
  7. 7(c)(i)Calculate the probability that the first patty selected was saltfish.[4 marks]

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