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Romelu picks a shirt and shorts - OCR - GCSE Maths - Question 24 - 2018 - Paper 1
Question 24
Romelu picks a shirt and shorts. The probability he picks a red shirt is 0.4. The probability he picks white shorts is 0.7. (a) Complete the tree diagram. Shirt ... show full transcript
Worked Solution & Example Answer:Romelu picks a shirt and shorts - OCR - GCSE Maths - Question 24 - 2018 - Paper 1
Step 1
Complete the tree diagram.
Answer
To complete the tree diagram, we need to determine the remaining probabilities based on the information provided.
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Since the probability of picking a red shirt is 0.4, the probability of not picking a red shirt is:
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Given that the probability of picking white shorts is 0.7, the probability of not picking white shorts is:
The completed tree diagram is as follows:
Shirt
├── Red (0.4)
│ └── Shorts
│ ├── White (0.7)
│ └── Not White (0.3)
└── Not Red (0.6)
└── Shorts
├── White (0.7)
└── Not White (0.3)
Step 2
Calculate the probability that Romelu picks a red shirt but does not pick white shorts.
Answer
To find the probability that Romelu picks a red shirt but does not pick white shorts, we can use the probabilities determined in the tree diagram.
The required probability is calculated as:
- Probability of picking a red shirt:
- Probability of picking not white shorts:
Therefore, the combined probability is:
Thus, the probability that Romelu picks a red shirt but does not pick white shorts is .