MFSS 2020 P2 Solution

2020 Computing Sec 4 Prelim Paper 1 Marking Guide Qn Answer 1 One mark for working top formula, one mark for rest =VLOOKUP($B2,$A$18:$D$23,4,TRUE) =VLOOKUP($B3,$A$18:$D$23,4,TRUE) =VLOOKUP($B4,$A$18:$D$23,4,TRUE) =VLOOKUP($B5,$A$18:$D$23,4,TRUE) =VLOOKUP($B6,$A$18:$D$23,4,TRUE) =VLOOKUP($B7,$A$18:$D$23,4,TRUE) =VLOOKUP($B8,$A$18:$D$23,4,TRUE) =VLOOKUP($B9,$A$18:$D$23,4,TRUE) =VLOOKUP($B10,$A$18:$D$23,4,TRUE) =VLOOKUP($B11,$A$18:$D$23,4,TRUE) =VLOOKUP($B12,$A$18:$D$23,4,TRUE) =VLOOKUP($B13,$A$18:$D$23,4,TRUE) 2 One mark for working top formula, one mark for rest =MIN(D2:F2) =MIN(D3:F3) =MIN(D4:F4) =MIN(D5:F5) =MIN(D6:F6) =MIN(D7:F7) =MIN(D8:F8) =MIN(D9:F9) =MIN(D10:F10) =MIN(D11:F11) =MIN(D12:F12) =MIN(D13:F13) 3 One mark for working top formula, one mark for rest =PMT(G2/12,12*C2,B2) =PMT(G3/12,12*C3,B3) =PMT(G4/12,12*C4,B4) =PMT(G5/12,12*C5,B5) =PMT(G6/12,12*C6,B6) =PMT(G7/12,12*C7,B7) =PMT(G8/12,12*C8,B8) =PMT(G9/12,12*C9,B9) =PMT(G10/12,12*C10,B10) =PMT(G11/12,12*C11,B11) =PMT(G12/12,12*C12,B12) =PMT(G13/12,12*C13,B13) 4 One mark for working top formula, one mark for rest =H2*C2*12 =H3*C3*12 =H4*C4*12 =H5*C5*12 =H6*C6*12

2 =H7*C7*12 =H8*C8*12 =H9*C9*12 =H10*C10*12 =H11*C11*12 =H12*C12*12 =H13*C13*12 5 One mark for working top formula, one mark for rest =I2+B2 =I3+B3 =I4+B4 =I5+B5 =I6+B6 =I7+B7 =I8+B8 =I9+B9 =I10+B10 =I11+B11 =I12+B12 =I13+B13 6a ans = random.randint(1,100) 6b count = 1 count += 1 print(count) 6c x = input("Enter a number: ") while not x.isdigit(): x = input("Enter only numbers: ") x=int(x) 7 while x != ans and count < 8: #1 mark correct loop if x == ans: #1 mark correct message print("Correct!") else: print("Wrong") 8 Single errors are underlined, errors requiring two corrections are in bold try1 = int(input(Enter distance for Attempt 1: ")) try1 = int(input("Enter distance for Attempt 2: ")) if try1 < try2: dis = try1 elif: dis == try2 if dis >= 245: print("5 Points") if dis >= 236: print("4 Points") elif dis >= 226: print("3 Points" elif dis >= 216: print("2 Points") elif dis >= 206:

3 print("1 Points") else print("6 Points") try1 = int(input("Enter distance for Attempt 1: ")) try2 = int(input("Enter distance for Attempt 2: ")) if try1 > try2: else: dis = try2 if dis > 245: elif dis >= 236: print("3 Points") else: print("0 Points") 9 List set up for World. Assign ‘A’ to first space (index 0) Use of loop to print world… …with proper control to print four correct spaces in each of four lines Note: Also accept use of string as data structure for world. world = ["."]*16 world[0] = 'A' for i in range(len(world)//4): line = "" for j in range(4): line += world[i*4 + j] print(line) print() 10 Input from user Variable set up for current Use of loop to iterate user input string with proper loop control Correct update of all spaces Correct printout world = ["."]*16 world[0] = 'A' for i in range(len(world)//4): line = "" for j in range(4): line += world[i*4 + j] print(line) print() sequence = input("Enter sequence") current = 0 print() for i in sequence: if i == 'w': current -= 4 elif i == 's': current += 4 elif i == 'a': current -= 1 elif i == 'd': current += 1 world[current] = 'A' for i in range(len(world)//4):

4 line = "" for j in range(4): line += world[i*4 + j] print(line) print() 11 A... A... AAAA ...A output matches stored program 12 Input from user for Player B Variable set up for current_b Correct use of second loop to iterate Player B’s sequence Check for spaces visited by both players world = ["."]*16 world[0], world[15] = 'A', 'B' for i in range(len(world)//4): line = "" for j in range(4): line += world[i*4 + j] print(line) sequence_a = input("Enter sequence for Player A: ") sequence_b = input("Enter sequence for Player B: ") current_a, current_b = 0, 15 for i in sequence_a: if i == 'w': current_a -= 4 elif i == 's': current_a += 4 elif i == 'a': current_a -= 1 elif i == 'd': current_a += 1 if world[current_a] == 'B' or world[current_a] == 'X': world[current_a] = 'X' else: world[current_a] = 'A' for i in sequence_b: if i == 'w': current_b -= 4 elif i == 's': current_b += 4 elif i == 'a': current_b -= 1 elif i == 'd': current_b += 1 if world[current_b] == 'A' or world[current_b] == 'X': world[current_b] = 'X' else: world[current_b] = 'B' for i in range(len(world)//4): line = "" for j in range(4): line += world[i*4 + j] print(line)

5 13 Input from user for size of world Adaption of all other parts of program side = int(input("Enter length of grid")) world = ["."]*side**2 world[0],world[side**2 - 1] = 'A','B' for i in range(len(world)//side): line = "" for j in range(side): line += world[i*side + j] print(line) sequence_a = input("Enter sequence for Player A: ") sequence_b = input("Enter sequence for Player B: ") current_a, current_b = 0, side**2 - 1 for i in sequence_a: if i == 'w': current_a -= side elif i == 's': current_a += side elif i == 'a': current_a -= 1 elif i == 'd': current_a += 1 if world[current_a] == 'B' or world[current_a] == 'X': world[current_a] = 'X' else: world[current_a] = 'A' for i in sequence_b: if i == 'w': current_b -= side elif i == 's': current_b += side elif i == 'a': current_b -= 1 elif i == 'd': current_b += 1 if world[current_b] == 'A' or world[current_b] == 'X': world[current_b] = 'X' else: world[current_b] = 'B' for i in range(len(world)//side): line = "" for j in range(side): line += world[i*side + j] print(line)