Question

In a competitive examination ,5 marks are awarded for each correct answer, while 2 marks are deducted for each wrong answer. Jayant answered 120 questioms and got 348 msrks .how many questions did he answer correctly

Answer 1

Let us suppose the no. of correct answers is x and wrong answers be y 
Then -
x + y = 120 
and 
5x  - 2y = 348            according to the given two conditions

solving eq. 1 
x = 120 - y 
putting this value in eq. 2 
5 (120-y) - 2y = 348 
600 - 5y -2y = 348 
-7y = 348 -600 = -252
y = -252 / -7 = 36 
so, x = 120 - 36 = 84
so, he answered 84 correct and 36 wrong answers.

Answer 2

Answer:

Step-by-step explanation:

x + y = 120 

and 

5x  - 2y = 348            according to the given two conditions

solving eq. 1 

x = 120 - y 

putting this value in eq. 2 

5 (120-y) - 2y = 348 

600 - 5y -2y = 348 

-7y = 348 -600 = -252

y = -252 / -7 = 36 

so, x = 120 - 36 = 84