Multiple choice

In a examination, a student has to answer $8$ questions out of $10$ questions. If questions $1$ and $10$ are compulsory, in how many ways can a student choose the questions?

  1. $20$
  2. $24$
  3. $28$
  4. $30$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Total questions = 10. Need to choose 8. Questions 1 and 10 are compulsory, so we need to choose 6 more from the remaining 8 questions. Number of ways = 8C6 = 8C2 = (8 * 7) / 2 = 28.

AI explanation

Since question 1 and question 10 are already compulsory, the student must choose the remaining 6 questions from the other 8 available questions. Using the combinations formula, this is calculated as 8C6. Solving this yields 8C6 = 8! / (6! * 2!) = (8 * 7) / 2 = 28.

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