In a competitive examination, 1 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?

Let x be the number of correct answers of the questions in a competitive examination, then (120 - x) be the number of wrong answers of the questions.

Hence, Jayanti answered correctly 100 questions.