Multiple choice

A math test contains 6 questions. In how many ways can a student answer exactly 4 questions if each question can be either answered or skipped?

  1. 15

  2. 20

  3. 30

  4. 60

  5. 120
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The student needs to choose exactly 4 questions out of 6 to answer. The number of ways to choose 4 questions from 6 is given by the combination formula 6C4, which is 6! / (4! * 2!) = (6 * 5) / 2 = 15.

AI explanation

Choosing exactly 4 questions from 6 to answer is a combination problem solved by 6C4. The calculation is 6! / (4! * 2!) = (6 * 5) / 2 = 15. The student can answer in 15 ways.

Keep practicing — related questions