Permutations & Combinations
Grade 11
Question:
<p>In IIT-JEE 2016, a multiple choice question has four alternatives in which two or more than two are correct. Number of ways in which this question can be answered, is :</p>
<p style="display:inline">9</p>
<p style="display:inline">11</p>
<p style="display:inline">12</p>
<p style="display:inline">10</p>
Step-by-Step Solution
Key Concept: The total number of ways to answer a multiple-choice question with two or more correct options is the sum of combinations selecting k elements from n for all k ≥ 2.
<p>Required number of ways = <sup>4</sup>C<sub>2 </sub>+ <sup>4</sup>C<sub>3</sub> + <sup>4</sup>C<sub>4 </sub>= 11</p>
Correct Answer: B