Class 11

Math

Co-ordinate Geometry

Straight Lines

In an examination there are three multiple choice questions and each question has $4$ choices. Number of ways in which a student can fail to get all answer correct is?

- $11$
- $12$
- $27$
- $63$

There are 4 choices for each question. So, there

are 4 ways to answer a question.

Number of ways to answer 3 questions

$=4×4×4$

$↓$ $↓$ $↓$

$1_{st}$ question $2_{nd}$ $3_{rd}$

$=64$

Out of 64 ways there is only one way which has

all the answers correct.

So, Number of ways in which a student can fail to get all answers

correct $=64−1$

$=63$