Question

# In an examination a candidate attempts 90% of the  questions. Out of these 70% of his answers are correct. Each questions carries 3 marks for the correct answers and -1 mark for the wrong answer. If the marks secured by the candidate is 243, what is the total number of questions?

Solution

## Let total No. of question be x So, questions attempted = 90x/100 = 9x/10 Correct questions answered = 70%  of 9x/10 = 63x/100 therefore, wrong answered = 30% of 9x/10 = 27x/100 Marks for correct answer =  3 * 63x/100 = 189x/100 Marks deducted for wrong answer = 1 * 27x/100 = 27x/100 by question, (189x/100) - (27x/100)  =  243 or 162x/100 = 243 hence x = (243*100)/162 = 150 ns.

Suggest corrections