In an entrance exam, 3 marks is awarded for every correct answer and (-1) for every wrong answer. If a student gets 38 marks after attempting all questions, find the number of questions answered correctly if the total questions were 70. Choose one
A) 38
B) 40
C) 27
D) 43
E) 56

Rationale: explanation : let x be the number of questions answered correctly . hence , number of questions whose answer were wrong = ( 70 – x ) 3 * x + ( 70 – x ) * ( - 1 ) = 38 4 x = 38 + 70 = 108 x = 27 answer c
Answer: C