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(b) An ATM personal identification number (PIN) consists of four numerical digits. Each digit can be selected from 0 to
Posted: Thu May 05, 2022 8:15 pm
by answerhappygod
- B An Atm Personal Identification Number Pin Consists Of Four Numerical Digits Each Digit Can Be Selected From 0 To 1 (110.97 KiB) Viewed 38 times
(b) An ATM personal identification number (PIN) consists of four numerical digits. Each digit can be selected from 0 to 9 and repetitions are allowed. How many different possible PINS are there if there are no restrictions on the choice of digits? (2 marks) (ii) In fact, there are restrictions on the choice of digits. The following choices are prohibited: (I) four identical digits; (II) any sequences of consecutive ascending or descending digits, such as 6543; (III) any sequences starting with 19 (birth years are too easy to guess). How many different valid PINs are there? (3 marks)