SQSS 2018 P1 Solution

1 Computing 2018 Prelim P1 Mark Scheme Question Answer Marks 1 Description Function Returns the number of non-empty cells in the given range references ● ● COUNT ● HLOOKUP Looks for data in row and use associated data in the same row ● ● COUNTA ● CEILING Returns number rounded up to an exact multiple of significance ● ● VLOOKUP ● FLOOR 3 Question Answer Marks 2 One mark for the correct answer and one mark for showing the relevant working 2a (2^0) + (2^3) + (2^4) + (2^7) = 1 + 8 + 16 + 128 (Working) = 153 (Answer) 2 2b C 1100 7 0111 (Working) 1100 0111 (Answer) 2 2c 189 / 16 is 11 remainder 13 (working) BD (Answer) 2 Question Answer Marks 3a Pharming is the interception of request sent from a computer to a legitimate website and redirection to a fake website to steal personal data or credit card details. 2 Phishing is the use of emails and fake websites that appear to be from reputable companies in order to steal personal information such as passwords and credit card details. 2

2 Question Answer Marks 3b Two factor authentication is the type of authentication that uses evidence from both something the user knows and something the user owns. 1 Select either of the following: - Possibility of interception when sent wirelessly to user’s mobile phone during transmission process - Secret algorithm is poorly chosen or accidentally revealed, may be able to find out how to generate OTP without the use of the token 1 Question Answer Marks 4a modem 1 4b NIC 1 4c router 1 4d network bridge 1 4e network hub 1 4f SSID 1 Question Answer Marks 5a To perform basic mathematical and logical operations. 1 5b § Data bus is used to transport data between memory and the processor. § Address bus is used to specify memory address information. Difference is that data bus transport data in bi-directional while address bus is uni-directional. 3

3 Question Answer Marks 6a RAM – Random Access Memory is the main memory where data and instructions are stored temporarily. ROM – Read Only Memory is where data and instructions that rarely need to be change or used for starting up. RAM is volatile whereas ROM is not. 3 6b (1/2 Mark for each point mention) Device 1 – External hard disc drive Method – Data stored on Magnetic material Advantage – Large storage capacity, relatively cheaper Disadvantage – Vulnerable to drops and mechanical shocks 2 Device 2 – Flash drives, Memory Cards Method – Data is stored in electronics circuits that have no moving parts Advantage – much faster, portable, not as vulnerable Disadvantage – Much more expensive 2 Alternative Device – CD ROM, DVD, Blu-ray Method – Data is stored as very small pits or indentations that can be read or written by a laser Advantage – Large storage capacity of up to gigabytes of data Disadvantage - Data can only be written once for some non-rewritable formats - lower maximum storage capacity than magnetic external storage - Vulnera