JWSS 2018 P2 Solution

_________________________________________________________________________ This document consists of 7 printed pages. [Turn over COMPUTING 7155/02 Secondary Four Express 28 August 2018 Paper 2 Practical (Lab-based) 0800 – 1030 MARKING SCHEME 2 hour 30 minutes MAXIMUM MARKS : 50 Jurong West Secondary School Preliminary Examinations 2018

2 JWSS Mid--Year Examination 2018 Computing 7155/02 Secondary 4 Express Task 1 [10 Marks] Question Answer Marks 1 =RANDBETWEEN(1, 888) Question Answer Marks 2 =MID(C8,5,1) =MID(C9,5,1) =MID(C10,5,1) =MID(C11,5,1) =MID(C12,5,1) =MID(C13,5,1) =MID(C14,5,1) =MID(C15,5,1) =MID(C16,5,1) =MID(C17,5,1) Question Answer Marks 3 =MAX(G8:G17)-MIN(G8:G17) Question Answer Marks 4 =COUNTIF(D8:D17,"F") Question Answer Marks 5 =VLOOKUP(E8,$B$26:$D$29,3,FALSE) =VLOOKUP(E9,$B$26:$D$29,3,FALSE) =VLOOKUP(E10,$B$26:$D$29,3,FALSE) =VLOOKUP(E11,$B$26:$D$29,3,FALSE) =VLOOKUP(E12,$B$26:$D$29,3,FALSE) =VLOOKUP(E13,$B$26:$D$29,3,FALSE) =VLOOKUP(E14,$B$26:$D$29,3,FALSE) =VLOOKUP(E15,$B$26:$D$29,3,FALSE) =VLOOKUP(E16,$B$26:$D$29,3,FALSE) =VLOOKUP(E17,$B$26:$D$29,3,FALSE) Question Answer Marks 6 one mark for correct HLOOKUP formula, one mark for the rest =HLOOKUP(G8,$C$20:$E$22,3,TRUE)*G8*F8

3 JWSS Mid--Year Examination 2018 Computing 7155/02 Secondary 4 Express Question Answer Marks 7 =SUM(H8:H17) Question Answer Marks 8 one mark for correct BOOLEAN AND formula, one mark for the CONDITIONAL IF =IF(AND(H22>190000, H20<8), "YES", "NO")

4 JWSS Mid--Year Examination 2018 Computing 7155/02 Secondary 4 Express Task 2 (Program Editing/Updating) [10 Marks] Question Answer Marks 9(a) num_words = 3 9(b) string_total = "" for ch in word: if ch.isalpha(): string_total = string_total + ch print("The concatenated alphabets in the word is", s) 9(c) while len(word)<=5: word = input("Enter an alphanumeric word with more than 5 characters: ") 10 num_words = int(input("Enter the number of words required: "))

5 JWSS Mid--Year Examination 2018 Computing 7155/02 Secondary 4 Express Task 3 (Program Correction) [10 Marks] Question Answer Marks 11 values = [] while True input_str = input("Enter integer, blank to end: ) if input_str = "": break values.prepend(int(input_str)) if len(Values) > 0: total = 0 index = 0 while index < len[values]: total = total + values[index] index += 1 average = total * len(values) elif: average = 0 print("The average of the given inputs is {".format(average)) Corrected Lines while True: input_str = input("Enter integer, blank to end: ") if input_str == "": values.append(int(input_str)) if len(values) > 0: Increase Indentation _index = 0 while index < len(values): average = total / len(values) else: print("The average of the given inputs is { } ".format(average))

6 JWSS Mid--Year Examination 2018 Computing 7155/02 Secondary 4 Express Task 4 (Program Creation) [20 Marks] Question Answer Marks 12 Program: input layers per shipment Variable set up for average_per_layer Variables set up and initialised accordingly for total and lists Use of loops Correct calculation of total eggs spoilt Correct calculation of average rounded to nearest whole number Question Answer Marks 13 Test: ten lines of output (4) (-1 for each line with an error) Output matches stored program Question Answer Marks 14 Correctly printing out layers that contain more than 19 eggs. Output matches stored program Question Answer Marks 15 Extension of program to include any number of layers