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:
74.7 km/h
Step-by-step explanation:
The computation of the average speed is shown below:
As we know that
Speed = Distance ÷ Time
where
Distance = 66 km
And, the time is from 14.54 to 15.47 is 53 minutes
So, the speed is
= 66 km ÷ 53 minutes
= 74.71698 kilometers per hour
= 74.7 km/h
Answer:
well if we are going by pattern them possibly 20 or 30 im sorry if its wrong i just need more info on how i should answer it
Step-by-step explanation:
Answer:
8x-3
Step-by-step explanation:
take a 2 out of each of them
Answer:
1. the first one - (100-2)*24 = 2400 - 48 = 2352
2. third one - (20+1)*15=300+15
3. fourth one - (0.5+0.01)*40 = 20+0.4 = 20.4
Step-by-step explanation:
