karnaidu wrote:

chetan2u wrote:

plalud wrote:

You have a 3 sided triangular pyramid and 4 cans of paint, each a different color. How many distinct ways can you paint the pyramid using a different color for each side? (If you can reorient the pyramid to look like another pyramid then the two pyramid are not distinct.)

(A) 2

(B) 4

(C) 6

(D) 8

(E) 20

3-sided triangular pyramid means all FOUR faces are triangles....

so we can make the base as one of vertical faces and vice versa..

so the way you colour 3 vertical faces will encompass all other when each face is converted as base one by one..

so we have to see how we can colour the 3 vertical faces..

now 3 vertical faces is nothing but a circular arrangement so ways (3-1)! = 2!=2 ways

A

Hii Chetan ..

It is clear for circular arrangement . But there are 4 different colors available . But why you are selecting colors only from 3 colors ??

If you say one color is applied to base , even in that case we have to select that color from 4 different paints available right ??

Please explain me in detail . I am confused with this question

Suppose your base 1 is red. Then other 3 faces are Green Blue and Yellow. If you keep this in your palm with red side on it, you can rotate this pyramid in 2 ways. Clockwise and anti clockwise.

Now lets change the base. Let the base be green and other faces be red yelloe blue. Now again when you try to rotate , the same figure is generated. So the total no of orientations is just two. Also keep in mind, we have only 4 paints and 4 faces to paint. Had there been more paints and lesser facs faces, situation would have been different.

Hope this makes sense.

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