in an examination , a student scores 4 marks for every correct answer and loses 1 mark for every wrong answer . if he attempts all 80 questions and secures 120 marks , how many questions does he answer correctly ?
"let the number of correct answers be x then , number of wrong answers = ( 80 - x ) 4 x – ( 80 - x ) = 120 = > 4 x – 80 + x = 120 = > 5 x = 200 = > x = 200 / 5 = 40 i . e . , he does 40 questions correctly answer is e ."
divide(add(120, 80), add(4, 1))