Question

In an examination, one mark is awarded for every correct answer while 1/2 mark is deducted for every wrong answer. A candidate answered 80 questions and got 60 marks. hote many questions did he answer correctly​

Answer 1

Answer:

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

Step-by-step explanation:

Answer 2

Answer:

let no:of questions incorrect be x

=> no:of questions correct = 80-x

so,

(no:of questions correct)(marks for every correct answer) - (no:of questions incorrect)(marks for every incorrect answer) = 60

=> (80-x)(1) - (x)(1/2) = 60

=> 80 - 3x/2 = 60

=> 160 - 3x = 120

=> 3x =