Question

In a competitive examination, one mark is awarded for each correct answer while
1
2
mark is deducted for every wrong answer. Jayanti answered 120 questions
and got 90 marks. How many questions did she answer correctly?

Answer 1

Answer:

let right answers be x and wrong answers been y

x+y=120

x=120-y and

x-2y=90

120-y-2y=90

3y=120-90

y=30/3=10

as x+y=120

x+10=120

x120-10=110