Your Venn diagram entries appear correct and are consistent with the 30 students
B) is correct
C) This a conditional probability
P(A | B) ---> read: the probability of A given B
= P(A and B)/P(B)
for yours:
P(Fruit | Salad)
= P(Fruit and Salad)/P(salad)
= (7/30) / (18/30)
= 7/18
Paula asked 30 students what they ate for lunch.
All the students had at least a sandwich, salad or fruit.
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QUESTION A
Draw a Venn Diagram.
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THIS IS THE INFORMATION FROM THE DIAGRAM:
5 students had a sandwich, salad and fruit.
3 students had a sandwich only.
7 students had salad only.
7 students had fruit only.
4 students had a sandwich and salad.
2 students had a sandwich and fruit.
2 students had salad and fruit.
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1 person is now chosen at random.
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QUESTION B
Find the probability that they have a sandwich but not fruit.
* * * * * * * * * * * * * * * * *
ANSWER: 7/30?
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QUESTION C
Given that the person has salad, find the probability that they also have fruit.
* * * * * * * * * * * * * * * * *
ANSWER: 7/18 or 7/25 or 7/30 or 7/14 = 1/2?
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2 answers
Thank you Reiny