The number of questions answered correctly = 90.
<h3>What is a system of linear equations?</h3>
- 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,
- x + y = 200 (For number of questions) (eqn 1)
- 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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Answer:
135
Step-by-step explanation:
if mK is 90 then mD is 60 and mS is 30. since the new point is in the middle of the triangle divide 60 and 30 by 2. Now mD is 30 and Ms is 15 so 30+15=45 so 180-45=135
Step-by-step explanation:
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Answer:
-15
Step-by-step explanation:
If it fell 3 deg every hour for 5 hours so the equation is 3*5 plus a - sign because it dropped degrees
-18 because 2 1/4 as an improper fraction is 9/4 then it -8/1 then multiply which is -72/4 and simplified is -18.
