Question

In a test (+5) marks are given for correct answers and (-2) marks are given for every incorrect answer. Riley answered all the question and scored 30 marks and got 10 correct answers. How many incorrect answers did she attempt?

Answer 1

Answer: If every 5 marks is one correct answer and she got ten correct then she should've gotten 50 marks but she only got thirty and 2 marks are taken away for every missed question which is a 20 difference so she should have 10 incorrect answers

Answer 2

Riley got 10 incorrect answers.

Explanation:

If she got 10 correct answers she got 50 marks because each correct answer gives +5 marks and 10×5 is 50.

However, in the end Riley got 30 Mark's and the difference between 50 and 30 is 20 so -20 marks is taken from 50.

Furthermore, each incorrect answer gives -2 marks and (-20÷-2 is 10) so Riley got 10 incorrect answers.