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

Answer:

20 questions

Step-by-step 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

$Incorrect\ Answers = \frac{-20}{-2}$

$Incorrect\ Answers = 10$

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