## Question

primary 6 | Maths | Measurement

Anyone can contribute an answer, even non-tutors.

##### Luis Tan

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Please provide a clear explenation. Thank you.

Date Posted: 1 year ago
Views: 119
J
1 year ago
Let the total number of questions be 5 units.

Then, she answered 1/5 of the questions wrongly. So that's 1 unit worth of questions.

1 - 1/5 = 4/5

So 4/5 of the questions were answered correctly. That's 4 units worth of questions.

5 marks were awarded.

So since 4 units worth of questions were answered correctly, marks awarded
= 4 units x 5 marks
= 20 units worth of marks

2 marks were deducted. You can treat this as though -2 marks were awarded.

So since 1 unit worth of questions were
= 1 unit x -2 marks
= -2 units worth of marks

So her total score
= 20 units worth of marks - 2 units worth of marks
= 18 units worth of marks

And we know her total score was 216 marks.

So 216 marks = 18 units worth of marks.

1 unit = 216 ÷ 18 = 12

So in 1 unit , there are 12 questions.

Total number of questions
= 5 units
= 12 questions x 5
= 60 questions