126 people are asked about their usual breakfast, 62 people have tea, 51 people have toast and 28 people have neither work out the probability a person chosen at random have both tea and toast

Statistics

ScanSolve AI Answer

4 steps

To find the probability that a person chosen at random has both tea and toast, we can use the principle of inclusion-exclusion.

  1. Total number of people surveyed: 126
  2. People who have tea: 62
  3. People who have toast: 51
  4. People who have neither: 28

First, we find the number of people who have either tea or toast or both:

Peoplewhohaveeitherteaortoast=TotalNeither=12628=98People who have either tea or toast = Total - Neither = 126 - 28 = 98

Using the inclusion-exclusion principle:

Peoplewhohaveteaortoast=Peoplewithtea+PeoplewithtoastPeoplewithbothPeople who have tea or toast = People with tea + People with toast - People with both

Let xx be the number of people who have both tea and toast:

98=62+51x98 = 62 + 51 - x

Solving for xx:

98=113xx=11398x=1598 = 113 - x \\ x = 113 - 98 \\ x = 15

Now, the probability that a person chosen at random has both tea and toast is:

Probability=NumberofpeoplewithbothTotalnumberofpeople=15126=542Probability = \frac{Number of people with both}{Total number of people} = \frac{15}{126} = \frac{5}{42}

Thus, the probability is 542\frac{5}{42}.

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