Kai has four differently numbered cards - OCR - GCSE Maths - Question 2 - 2023 - Paper 1
Question 2
Kai has four differently numbered cards.
- The range of the numbers is 14.
- The median of the numbers is 9.
- All the numbers are prime numbers.
- The lowest numbe... show full transcript
Worked Solution & Example Answer:Kai has four differently numbered cards - OCR - GCSE Maths - Question 2 - 2023 - Paper 1
Step 1
The range of the numbers is 14.
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Answer
The range is defined as the difference between the highest and lowest numbers. Given the lowest number is 5 and the range is 14, we can calculate the highest number as follows:
extHighestNumber=extLowestNumber+extRange=5+14=19
Step 2
The median of the numbers is 9.
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Answer
With four numbers, the median is calculated as the average of the two middle numbers when arranged in order. Let the numbers be represented as a1,a2,a3,a4 where a1<a2<a3<a4. Given the median is 9, we can set up the equation:
rac{a_2 + a_3}{2} = 9
ightarrow a_2 + a_3 = 18
Step 3
All the numbers are prime numbers.
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Answer
Prime numbers that can be considered include 5, 7, 11, 13, 17, and 19. Since the lowest number is 5 and the highest is 19, we need to find two other prime numbers that fit this criteria while also giving a median of 9.
Step 4
The lowest number is 5.
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Answer
From the previous step, we can choose 7 and 11 as the next two prime numbers. Arranging them gives us 5, 7, 11, and 19. Checking the median:
rac{7 + 11}{2} = 9
This is correct. Thus, the numbers on the cards in order are: 5, 7, 11, 19.