six faces of a cube

The number of ways in which the six faces of a cube be painted with six different colours is......

a]6

b]6!

c]6C2

d] none of these

18 Answers

62
Lokesh Verma ·

what is the justification of

now the rest 4 may be put on any of the side faces....they remain identical

62
Lokesh Verma ·

no they arent identical..

Bcos the two other faces are fixed..

Try this on a dice

you have 1 and 6 on opposite faces...

Try to reverse the numbering of 2, 3, 4, 5...

You wont get the same dice.

13
Двҥїяuρ now in medical c ·

plz...check this...i m not sure..

13
Двҥїяuρ now in medical c ·

but....one thing....

Now you have 4 colors and 4 faces.. each in a circular part

so the no of ways is 3!=6

here clockwise and anticlockwise arangements are identical....aren't they[7]

then should it be 3!/2[7]

hence the ans 5*3=15...or...6C2

62
Lokesh Verma ·

@bhargav..

Sorry dude I was not able to understand the opening up of the cube thing :(

could u elaborate mroe?

39
Dr.House ·

thats what i posted na bhaiyan.

62
Lokesh Verma ·

@abhirup:

no of ways you can arrange n ppl on a circular table?

(n-1)!

39
Dr.House ·

I HAVE A GUD WAY.OPEN UP THE CUBE AND SEE IT AS A CIRCULAR PERMUTATIONS. NOW ANSWER BECOMES 5P2

THATS 30.

13
Двҥїяuρ now in medical c ·

it is common sense ....na...

but bhaiyaa... why did you write 3! [7]

1
prateek punj ·

i think it shud be 6!...
but i don't think that it wud be so easy....

13
Двҥїяuρ now in medical c ·

the colour of the top face may be any of the 6.

now for it the colour of the bottom may be of 5 different.

now the rest 4 may be put on any of the side faces....they remain identical

so...5*6=30

bhaiyaa...i didn't get ur...3!

i m not convinced with my method.....

62
Lokesh Verma ·

The 6 faces are independent.

Color one of them and fix that.(and put it at the bottom)

So you have 5 faces left

the top face can be colored in 5 ways.

Now you have 4 colors and 4 faces.. each in a circular part

so the no of ways is 3!=6

so 5.6=30

13
Двҥїяuρ now in medical c ·

how....did u get 30???????

13
Двҥїяuρ now in medical c ·

how??....eureka??

1
prateek punj ·

can u tell us how...

24
eureka123 ·

none of these....ans is 30

1
prateek punj ·

hey buddy r all the faces identical....

13
Двҥїяuρ now in medical c ·

Try again....i will tell the ans later

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