Some people took part in the first round of a competition - Edexcel - GCSE Maths - Question 17 - 2021 - Paper 2
Question 17
Some people took part in the first round of a competition.
The histogram gives information about the scores of these people in the first round.
20% of the people go... show full transcript
Worked Solution & Example Answer:Some people took part in the first round of a competition - Edexcel - GCSE Maths - Question 17 - 2021 - Paper 2
Step 1
Find the total area under the histogram
96%
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Answer
To begin, the total area under the histogram represents the total number of participants. The area for each bar can be calculated by multiplying the width by the height:
For the first bar (0-10): Area = 10 x 2 = 20
For the second bar (10-20): Area = 10 x 3 = 30
For the third bar (20-30): Area = 10 x 2 = 20
For the fourth bar (30-40): Area = 10 x 1 = 10
Now, sum these areas:
Total Area = 20 + 30 + 20 + 10 = 80
This means a total of 80 people participated.
Step 2
Calculate 20% of the total number of people
99%
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Answer
To find out how many people scored high enough to qualify, calculate 20% of the total number of participants:
20% of 80 = 0.20 x 80 = 16.
Thus, 16 people qualified for the second round.
Step 3
Identify the qualifying score from the histogram
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Answer
Next, we look at the histogram to find the score corresponding to the top 16 people. The cumulative number of people scoring from the highest score downward:
From 30 to 40 (last bar): 10 people
From 20 to 30 (third bar): 20 people (cumulative total: 10 + 20 = 30)
From 10 to 20 (second bar): 30 people (cumulative total: 30 + 30 = 60)
From 0 to 10 (first bar): 20 people (cumulative total: 60 + 20 = 80)
To find the cutoff score for the top 16 qualifiers, we see that the last 10 people scored between 30 and 40, which indicates that the lowest qualifying score is 30.