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lisov135 [29]
3 years ago
5

In a test (+5) marks are given for every correct answer and (-2) marks are given for every incorrect answer . Roy answered all t

he questions and scored 30 marks though she got 10 correct? Find the total number of sums .
Mathematics
1 answer:
katovenus [111]3 years ago
3 0

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

<em>Hence, Roy answered a total of 20 questions</em>

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Answer:

100 is 40% of 250

Step-by-step explanation:

1. We assume, that the number 250 is 100% - because it's the output value of the task.  

2. We assume, that x is the value we are looking for.  

3. If 100% equals 250, so we can write it down as 100%=250.  

4. We know, that x% equals 100 of the output value, so we can write it down as x%=100.  

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7. Solution for 100 is what percent of 250

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100=2.5*x       - we divide both sides of the equation by (2.5) to get x

100/2.5=x  

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x=40

now we have:  

100 is 40% of 250

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