A bag contains 100 pencils that are either red or green - OCR - GCSE Maths - Question 11 - 2019 - Paper 1
Question 11
A bag contains 100 pencils that are either red or green.
Describe a method you could use to estimate the number of red pencils in the bag without looking into the b... show full transcript
Worked Solution & Example Answer:A bag contains 100 pencils that are either red or green - OCR - GCSE Maths - Question 11 - 2019 - Paper 1
Step 1
Step 1: Select a Pencil Randomly
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Answer
Firstly, take one pencil out of the bag without looking at it. Record the color of this pencil.
Step 2
Step 2: Repeat the Process
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Answer
Put the pencil back into the bag, and repeat the process multiple times, say 30 times. Each time, note down the color of the pencil taken out.
Step 3
Step 3: Calculate the Proportions
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Answer
After completing the trials, calculate the proportion of red pencils by dividing the number of red pencils drawn by the total number of pencils drawn. If R is the number of red pencils drawn and T is the total number drawn, then the proportion of red pencils can be expressed as:
Pred=TR
Step 4
Step 4: Estimate the Total Number of Red Pencils
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Answer
To estimate the total number of red pencils in the bag, multiply the total number of pencils in the bag (100) by the calculated proportion of red pencils:
