in an examination , a student scores 4 marks for every correct answer and loses 1 mark for every wrong answer . if he attempts all 75 questions and secures 125 marks , the number of questions he attempts correctly , is :
"explanation : let the number of correct answers be x . then numbers of incorrect answers will be 75 – x we get 4 x – ( 75 – x ) × 1 = 125 on solving the equation we get x = 40 answer : b"
divide(add(125, 75), add(4, 1))