TSS 2019 P1 Solution

2019 Prelim 4E Comp P1 Marking Scheme Question Answer Marks 1 Number Currency Text Date COUNTA √ RAND √ SMALL √ √ √ LEN √ 1 mark for each row 4 Question Answer Marks 2(a) Headings OR Header OR Field Name Text Not accepted: Title 2 2(b) ROUND() 1 2(c)(i) =VAR(E3:E18) 1 2(c)(ii) STDEV() 1 2(d) MODE.SNGL() 1 Question Answer Marks 3 PMT() calculates the instalment for a loan with compound interest. PPMT() calculates the portion of the instalment that is used to reduce the principal of the loan. Not accepted: monthly payment / principal payment 2 Question Answer Marks 4 Sum of place-values method, and Division-by-2 method 2 Question Answer Marks 5 Hexadecimal/ Binary Each character in the ASCII code is represented by a 2-digit hexadecimal or 7-bit binary 2 Question Answer Marks 6(a) Any 2 relevant points: Hackers may encrypt critical data and ask for ransom. OR Leaked or altered confidential data may compromise the proper operation of the university, e.g. exam papers and exam results. OR Personal and private data may be exposed, resulting in identity theft. E.g. NRIC numbers OR Intellectual property may be stolen or lost. Not accepted: Data is stolen (too vague) 2

6(b) Any 2 relevant points: Allow only authorized storage devices to be connected to the computer network. OR Use an email filter to block suspicious email and email attachments. OR Encrypt all important data so that hackers will not be able to read the data. OR Use encryption in data communication with between computers on the network. OR Isolate the Local Area Network from the Wide Area Network to prevent access from external computers. 2 Question Answer Marks 7(a) Phishing uses emails and fake websites that appear to be from reputable companies in order to steal personal information. Pharming intercepts requests sent from a computer to a legitimate website and redirects to a fake website to steal personal data. 2 7(b) A virus attaches itself to a harmless program and modifies it so that when it is run, the virus attaches copies of itself to other programs. A worm is a computer program that runs automatically and sends copies of itself to other computers. 1 mark if only mentioned about whether it attaches itself to a program 2 Question Answer Marks 8(a) Read the privacy policy of the organization. 1 8(b)(i) It may lead to identity theft if he does not use encryption when uploading the photo of the NRIC. OR It may lead to identity theft if he encounters a phishing website. OR It may lead to identity theft if his phone has a cloud service that backs up the NRIC photo to online servers without proper access control. Note: identity theft must be mentioned. 1 8(b)(ii) Ensure that the website uses public key encryption (padlock icon) or its address starts with “https:” OR Call the company first to verify that the website address is legitimate. OR Turn off clo