Q. In an examination there are three multiple choice questions and each question has 4 choices. Number of ways in which a student can fail to get all answers correct, is
A) 11
B) 12
C) 27
D) 63
Explanation
(d)
Each question can be answered in 4 ways and all question can be answered correctly in only one way.
So, required number of ways $= 4^{3} - 1 = 63$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.