AC Lim's answer to -'s Secondary 2 Maths Singapore question.
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Let correct answer = x
Wrong answer = y
Therefore,
x+y = 30
y = 30-x→①
5x -2y ≤ 66→②
Sub ① into ②,
5x -2(30-x) ≤ 66
5x -60 + 2x ≤ 66
7x ≤ 126
x ≤ 18.
Max answer correct = 18.
Hope this helps
Wrong answer = y
Therefore,
x+y = 30
y = 30-x→①
5x -2y ≤ 66→②
Sub ① into ②,
5x -2(30-x) ≤ 66
5x -60 + 2x ≤ 66
7x ≤ 126
x ≤ 18.
Max answer correct = 18.
Hope this helps
Date Posted:
3 years ago
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