# another puzzle

• Mar 6th 2006, 10:10 PM
bharathlece
another puzzle
17 In an examination a student must answer 65% of the questions
correctly. But it was found t hat after answer 7 questions corretly out of the
first 14, the student qualified. What is the min no. of questions in
the paper. (a) 22 (b) 18 (c) 20 (d) Can't say
• Mar 7th 2006, 01:33 PM
ThePerfectHacker
Quote:

Originally Posted by bharathlece
17 In an examination a student must answer 65% of the questions
correctly. But it was found t hat after answer 7 questions corretly out of the
first 14, the student qualified. What is the min no. of questions in
the paper. (a) 22 (b) 18 (c) 20 (d) Can't say

It is not possible, assume the worst case senario. That he answer 7 out of the first 14 and did not the rest. Then it is,
$\displaystyle \frac{7}{n}$ where $\displaystyle n$ is at least 14. In the best case senario (for the worst case) $\displaystyle n=14$ which is $\displaystyle \frac{7}{14}=$50% failure thus there is no answer.
• Mar 7th 2006, 07:35 PM
bharathlece
tahnk u
u really solved it briliantly.