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At the end of each year, a driver records how many kilometres they have driven - OCR - GCSE Maths - Question 23 - 2023 - Paper 3
Question 23
At the end of each year, a driver records how many kilometres they have driven. In 2021, they drove 18% more kilometres than in 2020. In 2022, they drove 25% more k... show full transcript
Worked Solution & Example Answer:At the end of each year, a driver records how many kilometres they have driven - OCR - GCSE Maths - Question 23 - 2023 - Paper 3
Step 1
Explain why 2625 is not the correct number of kilometres driven in 2020.
Answer
Kai's method assumes that a 25% reduction from 3500 km gives the total distance driven in 2020. However, the statement specifies that in 2022, 3500 km were driven, which is 125% of the 2020 figure (as he drove 25% more than in 2020). Therefore, to find the kilometres driven in 2020, we need to calculate:
Thus, 2625 km is incorrect because it does not accurately reflect what 125% of the original amount would reduce back to.
Step 2
Calculate the number of kilometres driven in 2021.
Answer
To find the number of kilometres driven in 2021, we first need to determine the kilometres driven in 2020, which we found to be 2800 km. The driver drove 18% more in 2021 compared to 2020, so we calculate:
Therefore, the number of kilometres driven in 2021 is 3304 km.