Question

A question paper contains $5$ questions each having an alternative. The number of ways that a student can answer one or more questions is

• A. $31$
• B. $242$
• C. $243$
• D. $32$

Answer 1

The correct option is B $242$

Each Question we have will have an alternative. So for each question we have $3$ ways.

i.e. correct, wrong or unattempted

So for $5$ questions, we have $3^5$ ways of answering the question.

But to solve one or more question $=$ Total $-$ (No one is correct which is only possible is 1 case).

Number of ways that a student can answer one or more questions $=3^5-1=242$