UPSC Prelims 2006·GS1·science-and-technology·science and technology

in a question paper, there are four multiple-choice questions. Each question has five choices with only one choice for its correct answer. What is the total number of ways in which a candidate will not get all the four answers correct?

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Last updated 23 May 2026, 3:31 pm IST
  1. A19
  2. B120
  3. C624Correct
  4. D1024

Explanation

To find the total number of ways a candidate can answer the questions, we look at the choices available for each question. Since there are four questions and each has five choices, the total number of possible combinations of answers is 5 multiplied by 5 multiplied by 5 multiplied by 5, which equals 625. Out of these 625 total combinations, there is only one specific combination where all four answers are correct. The question asks for the number of ways in which the candidate will not get all four answers correct. To find this, we subtract the one correct combination from the total number of possible combinations. Calculation: 625 total ways minus 1 correct way equals 624 ways. Therefore, 624 is the correct answer.
science-and-technology: in a question paper, there are four multiple-choice questions. Each question has five choices with only one choice for i
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