2025 TJC H2 Computing Prelims P1

© TJC 2025 [Turn over TEMASEK JUNIOR COLLEGE 2025 JC2 PRELIMINARY EXAMINATION Higher 2 COMPUTING 9569/01 Paper 1 Written 17th September 2025 3 hours READ THESE INSTRUCTIONS FIRST An answer booklet will be provided with this question paper. You should follow the instructions on the front cover of the answer booklet. If you need additional answer paper ask the invigilator for a continuation booklet. Answer all questions. Approved calculators are allowed. The number of marks is given in brackets [ ] at the end of each question or part question. The total number of marks for this paper is 100. This document consists of 7 printed pages and 1 blank page.

2 9569/01/2025 1 An ISBN is an International Standard Book Number and is a unique identifier for each book. Each ISBN consists of 13 digits, which is made up of 5 elements with each element being separated by spaces or hyphens. Three of the five elements may be of varying length:  Prefix element – currently this can only be either 978 or 979. It is always 3 digits in length  Registration group element – this identifies the country, geographical region, or language area participating in the ISBN system. This element may be between 1 and 5 digits in length  Registrant element – this identifies the publisher or imprint. This may be up to 7 digits in length  Publication element – this identifies the edition and format of a specific title. This may be up to 6 digits in length  Check digit – this is always the final single digit that mathematically validates the rest of the number. It is calculated using a Modulus 10 system with alternate weights of 1 and 3. An example of an ISBN with check digit 5 is shown below: (a) Describe a purpose of the check digit in an ISBN. [2] (b) Suggest another suitable validation technique for ISBN. [1] A school library system needs to store and search for information about books using their unique ISBNs. New books are added into the library inventory and damaged or older books are condemned from time to time. The developers propose the use of a hash table to store and retrieve the book records. (c) Explain how the library system would use a hash function and a hash table to store and search for books by their ISBNs. [3] (d) Give three features of an effective hashing algorithm. [3] (e) Explain the meaning of a collision in this context. [2] (f) Describe one method that can be used to handle the consequence of a collision. [2] Students on an internship with the library ask their developer mentors why the book records, ordered by their ISBNs, were not stored in a linked list instead. (g) Describe one disadvantage of storing and searching the records ordered by ISBNs using a linked list. [2] 978 - 92 - 95055 - 02 - 5 Prefix Registration group Registrant Publication Check digit

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