SPS 2019 P1

ST. PATRICK'S SCHOOL PRELIMINARY EXAMINATIONS 2019 SECONDARY 4 EXPRESS NAME CLASS INDEX NUMBER COMPUTING Paper 1 Written 7155/01 30 August 2019 2 h Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name, class, index number in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, 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 question. You should show all your working. The total number of marks for this paper is 80.

2 Parent’s Signature : ____________________________ Date: ____________________________ Remarks (if any) : For Examiner’s Use Marks /80 Total % This document consists of 11 printed pages including this page. 1 Draw a line to match the spreadsheet function to the correct description. Function Description ROUND Looks in the first column of an array and moves across the row to return the value of a cell COUNTA COUNT Returns the periodic payment for an annuity VLOOKUP Rounds a number to a specified number of digits HLOOKUP Counts how many values are in the list of arguments PMT [4] 2 A security system records video footage. One minute of video requires 180 MB of storage. The recording system can store several hours of video footage. (Computer Science P1, CIE 2015)

3 (a) Name and describe a suitable storage device for this recording system. [2] (b) Calculate how much storage would be needed for 2 hours of video footage. Show your working and give the answer in Gigabytes (GB). [2] 3 A car’s Engine Management System receives information from seven different sensors and stores the status of each sensor in an 8-bit register. A value of 1 indicates a fault condition. For example, a register showing 10110100 indicates: ● Engine overheating ● Airbag malfunction ● Low fuel (a) Identify the fault condition(s) that the following register indicates: 1 0 0 0 1 1 0 1 [2] (b) The system uses even parity. Write the correct parity bit in each of the following registers. 1 1 1 0 0 1 0 Parity Bit CO level too high Low voltage Airbag malfunction Engine overheat Low fuel Low oil level Brake pads too thin

4 0 1 0 1 0 1 0 [2] (c) State the hexadecimal value of the binary number shown in (a). [1] 4 In 2018, many Apple users received the following email notification allegedly from Apple’s billing department.

5 The hyperlink, titled “Click For Cancel or Downgrade >”, lea