2015 HC Software Design and Development

2015 HIGHER SCHOOL CERTIFICATE EXAMINATION

1110

Software Design and Development

General Instructions

•Readingtime–5minutes

•Workingtime–3hours

•Writeusingblackpen

•Drawdiagramsusingpencil

•WriteyourCentreNumberandStudentNumberatthetopofeitherpages29and31orpages35and39

Total marks – 100

Section I Pages2–9

20 marks

•AttemptQuestions1–20

•Allowabout35minutesforthissection

Section II Pages13–28

60 marks

•AttemptQuestions21–32

•Allowabout1hourand50minutesforthissection

Section III Pages29–40

20 marks

•AttempteitherQuestion33orQuestion34

•Allowabout35minutesforthissection

–2–

Section I

20 marksAttempt Questions 1–20Allow about 35 minutes for this section

Usethemultiple-choiceanswersheetforQuestions1–20.

1 Ateamhasbeencontractedtocreateasoftwarepackage.

Whichofthefollowingistheteam’smostappropriatefirststep?

(A) UseaGanttcharttoplanthedevelopment

(B) Lookforusefulmodulesinasoftwarelibrary

(C) Interviewtheclientforthesystemrequirements

(D) Createaprototypetoshowdifferentinterfacestyles

2 Acouncilwebsiteisbeingdevelopedtoallowresidentstonominateonedayoftheweekforgarbagecollection,andtoselectabinfromoneofthreesizes.

Whichcombinationofscreenelementswouldbebestforcapturingtheresidents’choicesofcollectiondayandbinsize?

Collection day Bin size

(A) Drop-downlist Radiobuttons

(B) Drop-downlist Checkboxes

(C) Textbox Radiobuttons

(D) Textbox Checkboxes

3 Whichofthefollowingisrepresentedinadataflowdiagram?

(A) Theorderinwhichprocessesoccur

(B) Wheredataoriginatesandwhereitisstored

(C) Thesequenceoftasksinvolvedincompletingaproject

(D) Thedecisionsthataremadewhensub-modulesarecalled

–3–

4 Itislegaltocopysoftwareandsellthecopiesif

(A) copyrightisacknowledged.

(B) thesoftwareisopensource.

(C) thesoftwarehasbeenpaidfor.

(D) thelicencespecifiesthatthisisallowed.

5 Someofthevariablesinaprogramaretobegivennewnames.

Whichdocumentationmustalsobemodified?

(A) Storyboard

(B) Datadictionary

(C) Systemflowchart

(D) Requirementsdefinition

6 Considerthisalgorithm.

BEGIN

N = 20

CASEWHERE N is

less than 10 : N = N + 5



OTHERWISE : N = N + 50

ENDCASE

Display N

END

Whatistheoutputofthealgorithm?

(A) 70

(B) 60

(C) 30

(D) 25

–4–

7 Howcantheinclusivityofacomputerprogrambeenhanced?

(A) Byreplacingpasswordcharacterswithasterisks

(B) Byprovidingarangeofmethodsforinputtingdata

(C) ByprovidingallthenecessarylibraryroutinesinasingleDLL

(D) Byensuringthatallsourceshavebeenincludedintheacknowledgements

8 Whichofthefollowingisusuallyabenefitofusingthepilotmethodofinstallation?

(A) Thedevelopmenttimeisreduced.

(B) Abackupofdataiscreatedforeachnewtransaction.

(C) Thepersonnelinvolvedcanbeavailabletotrainothers.

(D) CASEtoolscanbemoreeffectivelyused.

9 Whichrowofthetablebestmatchesthedataitemwithasuitabledatatype?

Data Item Data Type

(A) Atelephonenumber Boolean

(B) Onestudent’spersonaldetails Real

(C) Thestatusofaradiobutton Boolean

(D) Alistofwinninglotterynumbers Real

10 Whichrowofthetablecorrectlymatchesdocumentationwithitspurpose?

Documentation Purpose

(A) Logbook Recordingprogressandproblemsencounteredduringsoftwaredevelopment

(B) Storyboard Showingthelinksbetweenhardwaredevicesandthedatabeingprocessed

(C) IPOchart Testingthesystemforlogicerrors

(D) Benchmarkreport Showingtheorderofexecutionofprogrammodules

–5–

UsethefollowingalgorithmtoanswerQuestions11and12.

BEGIN

low = 1

END

high = n

n = number of elements in the array list

list(low) = list(high)

list(high) = list(low)

low = low + 1

high = high – 1

islow < n?

No

Yes

11 Whichofthefollowingcontrolstructuresisusedintheflowchart?

(A) Binaryselection

(B) Pre-testrepetition

(C) Post-testrepetition

(D) Multiwayselection

12 Originallythearraycalledlistcontainsfivenumbers.

1 3 5 7 9

Whatwilllistcontainafterthealgorithmisexecuted?

(A) 1 3 5 3 1

(B) 1 3 5 7 9

(C) 9 7 5 3 1

(D) 9 7 5 7 9

–6–

13 Whatistheroleoftheprogramcounter?

(A) Itstorestheaddressofthenextinstruction.

(B) Itcountsthenumberoftimesaloopisexecutedinaprogram.

(C) Itkeepstrackofthelinenumberinthesourcecodeasitisbeingtranslated.

(D) Itstoresthenumberofuserspermittedtosimultaneouslyaccessaprogram.

14 MoveMeisdefinedbythefollowingrailroaddiagram.

MoveMe

AngleLength

Move

WhichofthefollowingEBNFstatementsisacorrectrepresentationofMoveMe?

(A) MoveMe = Move { <Angle> <Length> }

(B) MoveMe = Move [ <Angle> <Length> ]

(C) MoveMe = Move { <Length> <Angle> }

(D) MoveMe = Move [ <Length> <Angle> ]

15 Adeveloperappliesreverseengineeringtoapieceofsoftware.

Whatisthedevelopertryingtoachieve?

(A) Toreverttoapreviousversion

(B) Toretrievetheoriginalsourcecode

(C) Tounderstandhowthesoftwareworks

(D) Toensurecompatibilitywitholderversions

–7–

16 The following algorithm is designed to allow theuser up to three attempts to enter acorrectpassword.

1 BEGIN

2 Count = 1

3 Flag = False

4 WHILE . . . . . . . . . . . . . . . . . .

5 GetPassword(PasswordAttempt)

6 IF PasswordAttempt is correct THEN

7 Flag = True

8 Display “Enter”

9 ELSE

10 Display “Incorrect”

11 Count = Count + 1

12 ENDIF

13 ENDWHILE

14 END

Whichofthefollowingcorrectlycompletesline4?

(A) Count < 3 OR Flag = True

(B) Count < 4 OR Flag = True

(C) Count < 3 AND Flag = False

(D) Count < 4 AND Flag = False

17 Anarraywasoriginally

4 5 10 7 7 .

Afteronepassofasort,thearraybecame

4 5 7 7 10 .

InwhichofthefollowingareALLthesortingmethodslistedcapableofproducingthisresult?

(A) Bubble,insertion

(B) Bubble,selection

(C) Insertion,selection

(D) Bubble,insertion,selection

–8–

18 Considerthefollowingalgorithm.

BEGIN

number = 5

WHILE number < 200

Display number

Increment number by 2

ENDWHILE

END

Whichofthefollowingalgorithmswillproducethesameoutput?

(A) BEGIN

REPEAT

Display number

number = number + 2

UNTIL number > 200

END

(B) BEGIN

FOR number = 2 to 100

Display number * 2 + 1

NEXT number

END

(C) BEGIN

number = 5

REPEAT

Display number

Increment number by 2

UNTIL number = 200

END

(D) BEGIN

FOR number = 5 TO 200 STEP 2

Display number

NEXT number

END

19 Afteranarrayissorted,itselementsappearinthefollowingorder.

–10 100.78 7.8 71

Whattype(s)ofdatadoesthearraycontain?

(A) Real

(B) String

(C) Realandinteger

(D) Stringandinteger

–9–

20 Diff(a, b, result)isasubroutinethatacceptstwonumbersasinput.Itreturns“yes”inresultifthedifferencebetweenthenumbersislessthan10.Otherwiseitreturns“no”.

Whichofthefollowingcodefragmentswouldbemostusefulfortestingthesubroutinewitharangeofvalues?

(A)

REPEAT

input a

input b

Diff(a, b, result)

UNTIL result = “yes”

(B)

result = “no”

input a

input b

IF b – a < 10 OR a – b < 10 THEN

result = “yes”

ENDIF

Display result

(C)

FOR x = 1 TO 100

input a

input b

Diff(a, b, result)

NEXT x

Display result

(D)

input again

WHILE again ≠ “no”

input a

input b

Diff(a, b, result)

Display result

input again

ENDWHILE

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© 2015 Board of Studies, Teaching and Educational Standards NSW©2015BoardofStudies,TeachingandEducationalStandardsNSW

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Office Use Only – Do NOT write anything, or make any marks below this line.

Centre Number

Student Number

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43933103511111 15360



Section II

60 marksAttempt Questions 21–32Allow about 1 hour and 50 minutes for this section

Answer the questions in the spacesprovided. These spaces provideguidance for the expected length ofresponse.

If you include diagrams in youranswer, ensure that they are clearlylabelled.

Extra writing space is provided onpages27and28.Ifyouusethisspace,clearly indicate which question youareanswering.

Write your Centre Number andStudent Number at the top of thispage.

Please turn over

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Question 21 (2marks)

OutlineTWOreasonsformaintainingsoftware. 2

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Question 22(4marks)

Describehowacompletedprogramcouldbetestedbeforeitisreleased. 4

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Question 23(7marks)

(a) Whatinformationaboutalibraryroutineshouldbedocumentedtoenableitsusebyotherprogrammers?

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(b) The subroutine CharTally(String, Char, Count) counts the number of times acharacter(Char)appearsinStringandreturnstheresultinCount.

Aone-dimensionalarraycalledStudentscontains20names.

Writeanalgorithmtocountthetotalnumberoftimesthatthelower-caseletter‘ f ’appearsinthearrayStudents.UsethesubroutineCharTallyinyouralgorithm.

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Question 24(3marks)

Usingexamples,distinguishbetweentheeffectsofruntimeerrorsandlogicerrors. 3

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Question 25(3marks)

Explainwhysoftwaredevelopersmayprovidefreeupdatesforpurchasedsoftware. 3

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Question 26(4marks)

Aclubhas200members.

Each member’s information is contained in an unsorted array of records calledMembers.TheIDforeachmemberisunique.

The following algorithm displays the name of a member after the member’s ID isentered.

BEGIN

Get MemberID

FOR Counter = 1 to 200

IF MemberID = Members(Counter).ID THEN

Display Members(Counter).Name

ENDIF

NEXT Counter

END

Rewritethealgorithmsothat:

• itdisplays‘Invalid ID’iftheIDenteredisnotfound

• thelinearsearchterminatesassoonasamember’snamehasbeendisplayed.

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Question 27(3marks)

Softwareapplicationsarenowcreatedtorunonarangeofportabledevices,suchas 3smartphonesandtablets,aswellasarangeofdesktopcomputers.

Outlinehowthisaffectssoftwaredevelopment.

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Question 28(7marks)

AchainofvideostoresisintroducinganATM-stylekioskthatwillenablecustomerstocopymoviestotheirownUSBdevices.

Thekioskwillprovidemovieinformation,enablepaymentandallowdownloadtoaUSBdevice.

(a) Discussthesuitabilityofboththeprototypingandrapidapplicationdevelopmentapproachesfordevelopingthissystem.

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Question28(continued)

(b) Thekioskinterfacewillincludethefollowingfeatures:

• asearchoption

• alistofmoviesresultingfromasearch

• abilitytochoosetoseedetailsofaselectedmovie

• paymentanddownloadinstructions.

Astoryboardisbeingproducedtorepresenthowthekioskinterfacewilloperate.Thefirstscreenofthestoryboardisshownbelow.

Completethestoryboard.Notethatwithineachscreenthereneedonlybeatitleandnecessarybuttons.

Search movies

SEARCH screen

End of Question 28

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Question 29(9marks)

A program is required to operate an online shopping service. The following algorithm waswrittenbyadeveloperatanearlystageofdevelopment.

BEGIN Main VegPrice = 0 MeatPrice = 0 Display menu Input MenuChoice WHILE MenuChoice is not “Finish” CASEWHERE MenuChoice is “Vegies” : Veg (VegPrice) “Meat” : Meat (MeatPrice) ENDCASE Display menu Input MenuChoice ENDWHILE ShowTotal (VegPrice, MeatPrice, Total)END Main

BEGIN Veg (VegPrice) Display “Veg module called” VegPrice = 10END

BEGIN Meat (MeatPrice) Display “Meat module called” MeatPrice = 20END

BEGIN ShowTotal (VegPrice, MeatPrice, Total) Total = VegPrice + MeatPrice Display VegPrice, MeatPrice, Total get confirmation IF confirmation = True THEN Pay (Total) ELSE Clear ENDIFEND

BEGIN Pay (Total) Display “Pay module called” Display TotalEND

BEGIN Clear Display “Clear module called”END


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(a) WhatpurposedoestheMainmodulehavefortheuser?

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(b) ThealgorithmcontainsthestubsVeg,Meat,PayandClear.

Explainthepurposeofthesestubsindevelopingthisprogram.

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(c) Drawastructurechartcorrespondingtothealgorithmshown. 4

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Question 30(5marks)

A car dealership maintains information about all the cars that it has for sale. Theinformationabouteachcarincludes:

• ID

• Make

• Model

• Manual/Auto

• Price

• Yearofmanufacture.

Adeveloperisrequiredtowriteaprogramwhich:

• maintainsrecordsofcarsboughtandsold

• enablesdealerstosearchforcarsthatmeetdifferentspecifications.

(a) Whyisanarrayofrecordsappropriateformanipulatingthisdata?

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(b) Discusswhetherthedatainthearrayofrecordsshouldbesorted. 3

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Question 31(9marks)

Validserialnumbersforadevicemustbe:

• 5charactersinlength

• startwitha#symbol

• contain3digits

• endwitha#symbol.

Forexample,#123#isavalidserialnumber.

Thefollowingalgorithmwasdesignedtocheckifagivenserialnumberisvalid.

1 BEGIN

2 Input SerialNumber and store the characters in the array of characters called Serial

3 Valid = False

4 IF (Length of SerialNumber = 5) AND (Serial(1) is “#”) THEN

5 FOR Counter = 2 to 5

6 IF Serial(Counter) is a digit THEN

7 Valid = True

8 ELSE

9 Valid = False

10 ENDIF

11 NEXT Counter

12 ENDIF

13 IF Serial(5) is not “#” THEN

14 Valid = False

15 ENDIF

16 Display Valid

17 END

(a) Deskcheckthealgorithmusingtheserialnumber#1k3#asinput. 3

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(b) Thealgorithmcontainserrors.Showhowthealgorithmshouldbemodifiedtocorrecttheerrors.

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(c) List testdatanecessarytotest thelogicof thealgorithm.Justifyeachiteminyourlist.

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Question 32(4marks)

A computer game based on cards numbered from 1 to 28 is to be developed. The28cardsarestoredrandomlyinanarraycalledCards.Anexampleisshown.

4

Cards

8 1 7 5 11 … … … 12 26 13 19 14 22

Therearefourplayersandeachplayerisdealtsevencards.Anarrayisassignedtoeachplayerforstoringtheircards.TheplayersaregivencardsfromthearrayCardsonecardatatimestartingwithPlayer 1,thenPlayer 2,Player 3,Player 4,andthenbacktoPlayer 1,Player 2,Player 3,Player 4andsoon.

Examplesoftheplayers’arraysareshown.

Player 1

8 11 4 3 17 27 13

Player 2

1 9 2 10 20 28 19

Player 3

7 21 16 15 25 12 14

Player 4

5 18 23 6 24 26 22

WriteasubroutinecalledDealCardstodistributethecardsfromthearrayCardstoeachofthefourplayers.Inyouralgorithm,includeappropriatecontrolanddatastructures.

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If you use this space, clearly indicate which question you are answering.

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Section II extra writing space

If you use this space, clearly indicate which question you are answering.

©2015BoardofStudies,TeachingandEducationalStandardsNSW

–29–

Centre Number

Student Number

83293100401112 15360



Section III

20 marksAttempt either Question 33 or Question 34Allow about 35 minutes for this section

Answerthequestioninthespacesprovided.Thesespacesprovideguidancefortheexpectedlengthofresponse.

Ifyouincludediagramsinyouranswer,ensurethattheyareclearlylabelled.

Question 33 — Programming Paradigms (20marks)

(a) An e-learning application, composed of various types of activities, is to bedeveloped.

Eachtypeofactivitywillhave:

• auserinterfacespecification

• prerequisiteconditionsthatstudentsmustmeetbeforetheycanuseit.

Whenanactivityiscompleted,theapplicationsuggestsfurtheractivitiesbasedonthestudent’sinterestsandhowwellthestudentcompletedtheactivity.

Discussthesuitabilityofthelogicparadigmandtheobjectorientedparadigmfordevelopingthisapplication.

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(b) Usinganexample,outlinewhyheuristicsareusedinsomesoftwaresolutions.

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(c) Thisisafragmentoflogicparadigmcode,with

• salary(P,S) definedas‘thesalaryofpersonPisamountS’

• employer(P,E) definedas‘theemployerofpersonPisemployerE’.

salary(kim,56000).

salary(chris,23000).

salary(jay,46000).

salary(al,51000).

salary(jo,61000).

employer(chris,kim).

employer(kim,jay).

employer(al,jay).

employer(sam,jay).

valuable_employee(X):- employer(X,_) , salary(X,S) , S > 50000.

(i) Extendthefragmentofcode,usingfactsonly,sothatLingisavaluableemployee.

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(ii) Evaluatevaluable_employee(E)?.Showreasoning.

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Section III (continued)

5499310056153601113


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(d) Acustomcarmanufacturermakescarstoorderbasedoncustomers’selectionsofcomponents.Eachcomponentmaybestandardorspecialised.

The cost of a car is calculated by totalling the costs of all components. Thecostofeachstandardcomponentisfixed.Thecostofaspecialisedcomponentiscalculatedbyaddingthecostofthespecialisationtothecostofthestandardcomponent.

Thesoftwaretomanagecustomers’selectionsisbeingdeveloped.Thisfragmentofcodehasbeendesignedtobepartofthesoftware.

class Car {

private –

components: array of Component

public –

cost():

sum = 0

FOR i = 1 TO number of components

sum = sum + components[i].cost()

NEXT i

return sum

}

class Component {

public –

cost(): REM returns the cost of the component

}

(i) Explain how polymorphism AND inheritance can be used in thedevelopmentofthissoftware.

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(ii) Astandardenginecosts$2000,butaV8enginecostsanextra$800.

Writethecost()methodtocalculatethecostofinstancesofthefollowingsubclassesofComponent.

class Engine {

is a Component

}

class V8Engine {

is a Engine

}

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(e) The following fragment of code from the object oriented paradigm wasdeveloped to declare an array that alwayskeeps all its items in sortedorder,whennumbersareaddedorremoved.

Themethodsadd()andremove()alwayscallthemethodsort().Themethodsort()callsthemethodswap().

class SortedArray {

private –

items: array of integer

size: integer

public –

sort():

swap(index1, index2):

tmp = items(index1)

items(index1) = items(index2)

items(index2) = tmp

add(number):

remove(index):

}

Thecodecontainsanerror.

Explaintheconsequencesoftheerrorandshowhowitcanbecorrected.

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End of Question 33


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85433101161114 15360




Do NOT attempt Question 34 if you have already attempted Question 33.

Question 34 — The Interrelationship between Software and Hardware (20marks)

(a) Perform the calculation of 10111 × 111 using binary arithmetic, showing allnecessaryworking.

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(b) What are the benefits of using 2’s complement to represent integers incomputers?

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(c) Acomputer-controlledcuttingtoolcutsstraightlines.

Datastreamssentfromthecomputertothetoolaremadeupof16-bitpacketswiththefollowingstructure.

1

A BT X

1 0

Y

A: start bits, always 1 1

T: tool setting bit

0 = Tool up (not cutting)

1 = Tool down (cutting)

X: 6 bits specifying the X-coordinate to which the cutter moves

Y: 6 bits specifying the Y-coordinate to which the cutter moves

B: stop bit, always 0

(i) Thefollowingdatastream, inhexadecimalform, issent to thecuttingtool

3

D 6 A 0.

Eachhexadecimaldigitrepresents4bitsofthedatastream.

Describewhatthisdatastreamachieves.

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(ii) ThecuttingtooliscurrentlyatX = 0, Y = 0.

Writethedatastreamneededtocutthepatternshownbelow.

3

0 15 30 450

15

Y

X

30

45

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(d) Inbinary,thedecimalfraction7.5is111.1.

InIEEE754singleprecisionfloatingpointrepresentation,thedecimalfraction–7.5is:

4

1 10000001 11100000000000000000000

Identify the THREE components of the single precision floating pointrepresentationandoutlinehowtorepresent–7.5inthisnotation.

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8432310089153601115

–40–

5391310080


(e) Acarhasanalarmsystemwhichworksasfollows:

• Analarmwillsoundifthekeyisintheignitionandthedriver’sdoorisopen.

• The alarmwill also sound if thekey is not in the ignitionwhile the lights areon.

Inyouranswerstothequestionsbelow,usethefollowing:

Component 1 0

Key In ignition Not in ignition

Door Open Closed

Lights On Off

Alarm On Off

(i) Drawatruthtableforthisalarmsystem. 3

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(ii) Drawalogiccircuittorepresentthissystem. 3

End of paper


2015 HC Software Design and Development

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