In a question paper, there are four multiple choice type questions, each question has five choices with only one choice for it's correct answer. What is the total number of ways in which a candidate will not get all the four answers correct?
Correct answer: C. 624
- A. 19
- B. 120
- C. 624
- D. 1024
Explanation
Each of the 4 questions has 5 choices, so there are 5 x 5 x 5 x 5 = 625 answer patterns. Exactly 1 pattern has all four answers correct, leaving 625 - 1 = 624 patterns that are not completely correct; 1024 would incorrectly use 2 choices per question.
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