2021 ACSBR Computing P1 with Solutions

This paper has 14 pages, inclusive of the cover page. Name: Class: Index Number: Anglo-Chinese School (Barker Road) PRELIMINARY EXAMINATION 2021 SECONDARY FOUR EXPRESS COMPUTING PAPER 1 7155/01 2 HOURS INSTRUCTIONS TO CANDIDATES: Do not open this booklet until you are told to do so. Write your name and index number clearly in the spaces at the top of this page. Write in dark blue or black pen. You may use soft pencil for any diagrams, graphs or rough working. Do not use staples, paper clips, highlighters, glue or correction fluid. Approved calculators are allowed. Answer all questions. The number of marks is given in brackets [ ] at the end of each question or part of question. You should show all your working. The total mark for this paper is 80. TOTAL 80

Anglo-Chinese School (Barker Road) Preliminary Examination 2021 2 Secondary 4 Express Computing 7155/01 1 A bank uses spreadsheet software for computing its loans. Draw a line between the spreadsheet function and its description. Function Description • Calculate the interest payment for a given period PPMT • • Calculate the amount of money to be paid at the end of the loan FV • • Calculate the required interest rate per period of a loan RATE • • Calculate the instalment for a loan PMT • • Calculate the amount of money to be loaned • Calculate the principal payment for a given period [4]

Anglo-Chinese School (Barker Road) Preliminary Examination 2021 3 Secondary 4 Express Computing 7155/01 2 A digital clock is controlled by a microprocessor. It uses the 24 hour clock. The hour is represented by an 8-bit register, A, and the number of minutes is represented by another 8-bit register, B. (a) Show how 13:46 can be represented by these two registers. [2] (b) State the hexadecimal representation of the following two registers. Hours (hex) Minutes (hex) [2] (c) State the minimum number of bits that can be used to represent a 24 hour clock Hours bits Minutes bits [2] 3 Program development typically occurs across five distinct stages. (a) List any two stages in developing a program. 1 2 [2] (b) Describe what is “agile” software development. [2]

Anglo-Chinese School (Barker Road) Preliminary Examination 2021 4 Secondary 4 Express Computing 7155/01 4 Computers comprise various electronic components and hardware. (a) The table contains hardware commonly used with a computer. Tick () one or more boxes in each row to indicate if the hardware is an input, output or storage device. Hardware Input device Output device Storage device Speakers Processor register Touchscreen monitor Microphone [4] (b) Complete the following table for the types of external storage: Type Example Advantage Disadvantage Optical Large storage capacity of up to giga