Sasha is trying to remember a 4-digit pin number - OCR - GCSE Maths - Question 12 - 2023 - Paper 2
Question 12
Sasha is trying to remember a 4-digit pin number.
Sasha knows it has the following digits and that the first digit is 9.
9 3 2 7
(a) Write down all of the possible... show full transcript
Worked Solution & Example Answer:Sasha is trying to remember a 4-digit pin number - OCR - GCSE Maths - Question 12 - 2023 - Paper 2
Step 1
Write down all of the possible orders for Sasha’s 4-digit pin number.
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Answer
Given the digits 9, 3, 2, and 7, with the first digit fixed as 9, the possible 4-digit PIN numbers are ordered permutations of the remaining digits:
9327
9372
9237
9273
9732
9723
Thus, the possible orders for Sasha's 4-digit PIN number are:
9327
9372
9237
9273
9732
9723
Step 2
Write down the probability that the last digit of the pin number that Sasha tries is 2.
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Answer
Out of the 6 possible PIN numbers derived from the previous step, only the combinations 9327 and 9372 have 2 as the last digit. Therefore, the probability can be calculated as: