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Conditional Probability

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Question 49

A researcher surveys 100 teenagers about their social media usage. The apps tracked are Snapchat (SSS), Instagram (III), and TikTok (TTT).

  • 10 teenagers use all three apps
  • 20 teenagers use both Snapchat and Instagram
  • 18 teenagers use both Instagram and TikTok
  • 25 teenagers use both Snapchat and TikTok
  • 50 teenagers use Snapchat
  • 45 teenagers use Instagram
  • 55 teenagers use TikTok
a.

Draw a Venn diagram to represent this information.

[3]
b.

One of the teenagers is selected at random. Given they use TikTok, find the probability they do not use Instagram.

[3]

Conditional Probability Questions

  1. A Level
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  3. /Conditional Probability