Subject: General Aptitude · Chapter: Permutations and Combinations · Exam: 2012 · Marks: · Difficulty:
In an examination there are three multiple choice questions and each question has 4 choices. The number of ways in which a student can fail to get all answers correct is
(a)11
(b)27
(c)12
(d)63
Answer
Answer (as printed): D
Explanation
Number of ways of attempting the 1st, 2nd and 3rd questions are 4 each. Total number of ways $=4^{3}=4\times4\times4=64$. Number of ways of getting all answers correct $=1^{3}=1$. ∴ Number of ways of not getting all answers correct $=64-1=63$.
Explanation as extracted from the printed page; notation may be imperfect.