true

Take Engineering Entrance Coaching from the Best Tutors

Affordable fees
1-1 or Group class
Flexible Timings
Verified Tutors

Search in

Derangements, Arrangement Of Things So That No Elements Appear In Their Original Place (Important for IITJEE)

Sujoy Das

31/01/2018 3 0

"Like if I have 5 tshirts and i want to gift them to my 5 cousins named A,B,C,D,E, so find number of ways in which particular cousin won't get their particular tshirts."

So number of ways:

D(n)=n!(1-1/1!+1/2!-1/3!+.....(-1)^n1/n!))

Where n is number of things which don't go to their original position
here in this question n = 5

So 5!*(1-1/1!+1/2!-1/3!+1/4!-1/5)) = 44 ways in which 5 tshirts won't go to their original position

D(1) = 0

D(2) = 1

D(3) = 2

D(4) = 9

D(5) = 44

D(6) = 265 (( remember these values of Dearangements )).

3 Like 0 Dislike

Follow 5

Other Lessons for You

Problem on limits

Find: limit x→16 ( x¼ - 2 ) / (x - 16) We can rewrite the problem as limit x→16 ( x¼ - 16¼ )/(x - 16). [ use standard formula of. limit x→a {(x^n - a^n)/(x...

B.Sudhakar

4 0

Maths: Chapter 1: Euclid's Division Lemma

Anshuman Rai

0 0

Its only about happiness.

Do more no of problems on each topic ,so that you can go ahead confidently. Get familiar with practical aspects of what you are going through.

Priyabrata Biswal

0 0

Tip of the day

Try to get the logic behind the problem dont ever waste the time by thinking about answer

B.Manikanta

0 0

Mathematics Formula Sheet and Materials For Students

Parijat B.

0 0

Find Engineering Entrance Coaching classes near you

Online Engineering Courses

Looking for Engineering Entrance Coaching classes?

Learn from Best Tutors on UrbanPro.

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you

Engineering Entrance Coaching Questions

How do I clear concepts of physics?

5 Answers

What is the best way to master physics?

5 Answers

For physics, is HC Verma good?

6 Answers

Looking for Engineering Entrance Coaching Classes?

The best tutors for Engineering Entrance Coaching Classes are on UrbanPro

Select the best Tutor
Book & Attend a Free Demo
Pay and start Learning

Take Engineering Entrance Coaching with the Best Tutors

The best Tutors for Engineering Entrance Coaching Classes are on UrbanPro

I am a Student I am a Tutor
Name*	Please enter your full name. Please enter institute name.
Email*	Please enter your email address.
Phone*	Please enter a valid phone number.
Location*	Please enter a pincode or area name.
City*	Please enter city name.
Category*	Please enter category.
Gender*	Male Female Please select your gender.
Email ID/ Mobile No.*	Please enter either mobile no. or email.
Enter Password*	Please enter OTP Please enter Password Sorry, this phone number is not verified, Please login with your email Id.