Q. 225.0( 1 Vote )

# Mark the correct alternative in the following:In a room there are 12 bulbs of the same wattage, each having a separate switch. The number of ways to light the room with different amounts of illumination isA. 122 – 1B. 212C. 212 – 1D. none of these

In the room there are 12 bulbs of same wattage, each having separate switch.

We have 2 options for each bulb i.e. either switching it ON or to switching it OFF.

The 1st bulb can be switched ON or OFF i.e. 2 choices.

The 2nd bulb can be switched ON or OFF i.e. 2 choices, and so on.

Now, for 12 bulbs we have total 212 choices.

But, as we have to illuminate the room, so the single choice in which all the 12 bulbs are OFF should be omitted.

So, we have total (212 – 1) ways to light the room with different amounts of illumination.

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Circular permutations61 mins
Challenging Quiz on P&C | Test Yourself55 mins
Permutations & Combinations | Analyze your learningFREE Class
Understand Permutations like never before60 mins
Check Your progress Part 2| Interactive Quiz: Permutation & CombinationFREE Class
Interactive Quiz on Combinations-0253 mins
Interactive Quiz on Combinations50 mins
Division and distribution of objects58 mins
Lecture on Combinations49 mins
Interactive Quiz on Division and distribution of objects17 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
view all courses