Question

In a competitive examination, one mark is awarded for each correct answer while half mark is deducted for every wrong answer, jayanti answered 120 question correctly and got 90 marks. How many questions did she answer correctly?​

Answer 1

Answer:

Let x be the number of correct answers and y be the number of wrong answers.

Since Jayanti answered 120 questions therefore, x+y=120 that is

x=120−y..........(1)

Also, it is given that one mark is awarded for each correct answer while 2/1 mark is deducted for every wrong answer and Jayanti got 90 marks, therefore,

x−0.5y=90..........(2)

Substituting the value of equation 1 in equation 2:

120−y−0.5y=90

−1.5y=−30

y=20

Therefore,

x=120−20=100

Hence, she answered 100 questions correctly.

Answer 2

Answer:

Explanation:

Let x be the number of correct answers and y be the number of wrong answers.

Since Jayanti answered 120 questions therefore, x+y=120 that is  

x=120−y..........(1)

 

Also, it is given that one mark is awarded for each correct answer while  

2

1

​  

 mark is deducted for every wrong answer and Jayanti got 90 marks, therefore,

x−0.5y=90..........(2)

Substituting the value of equation 1 in equation 2:

120−y−0.5y=90

−1.5y=−30

y=20Therefore,  

x=120−20=100

Hence, she answered 100 questions correctly.

hope it helps

pls mark my answer as brainliest