Question

In a test (+5) marks are given for every correct answer and (-2) marks are given for every incorrect answer . Roy answered all the questions and scored 30 marks though she got 10 correct? Find the total number of sums .

Answer 1

20 questions

Explanation:

Given

`Correct \Marks= +5`

`Incorrect\ Marks= -2`

`Score\ Obtained = 30`

`Number\ of\ correct\ answers = 10`

Required

Number of questions answered

First, we need to get the total correct marks obtained by Roy

This is calculated by multiplying the correct marks by number of correct answers

`Total = +5 * 10`

`Total = +50\ marks`

Subtract this from the total scores obtained; This gives the total incorrect answer obtained by Roy

`Incorrect = Scores\ Obtained - Total`

`Incorrect = 30 - (+50)`

Open bracket

`Incorrect = 30 - 50`

`Incorrect = -20`

Divide this by -2 to get the number of incorrect answers

`Incorrect\ Answers = (-20)/(-2)`

`Incorrect\ Answers = 10`

Add this to the number of correct answers to give the total number of question answered

`Total = Correct\ Answers + Incorrect\ Answers`

`Total = 10 + 10`

`Total = 20`

Hence, Roy answered a total of 20 questions