Question

find the permutation in the word fission

Answer 1

Fission has 7 letters.
Ordinarily we would have 7! (seven factorial) ways to permute it, but...(more coming)

Answer 2

...but some letters are the same. We have 2 i's and 2 s's.

Answer 3

So we would divide 7! by 2! * 2! (to get rid of copies) to get
7!
----
2! 2!

Answer 4

It will be 7!/2!2! because i and s is repeating.

Answer 5

does that make sense?

Answer 6

So 7*6*5*4*3*2*1/2*1 x 2*1

Answer 7

And then you can cancel

Answer 8

Nope..

Answer 9

Multiply and divide.

Answer 10

5040/4 =1260 ans.

Answer 11

Maybe it's just me, but I always like to cancel before I multiply/divide.

Answer 12

Yeah we are taught in different way..anyway answer comes the same.