Question

if there are 200 questions and 4 marks for correct answers and -1 for incorrect answer and total marks is 250then what is the number of correct answers

Answer 1

The number of questions answered correctly = 90.

What is a system of linear equations?

• A system of linear equations is a set of two or more linear equations.
• Linear equations refer to the equations that involve two or more variables in the form of "ax + b".

Now,

Given:

• Total number of questions = 200
• Marks for correct answer = 4
• Marks for incorrect answer = -1
• Total marks = 250

To find : Number of correct answers = ?

Finding:

Now, assuming that the student attempted and answered all the questions,

• Let the number of questions correctly answered be x and incorrectly answered be y.

Then,

1. x + y = 200 (For number of questions) (eqn 1)
2. and 4x - y = 250 (For the marks scored) (eqn 2)

Solving the system of linear equations:

For eqn 2, we get that y = 4x - 250

Substituting in eqn 1, we get:

=> x + 4x - 250 = 200

=> 5x = 250 + 200 = 450

=> x = 90

That is, the number of questions answered correctly = 90, the incorrect answers = 200 - 90 = 110.

To learn more about system of linear equations, refer to the link: brainly.com/question/2226590

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