Time to dust off those old rubiks cubes

[Space cat]

All this cube stuff has reminded me of a puzzle I call Decorator's Dilemma.

You've taken a door off for painting and stood it against a wall - in a corner. You can paint the front, the top and the right hand edge only. You have no access to the other three surfaces. How many painting sessions do you need to complete the job?

 

[tim west]

All the doors sufaces have to be painted?

 

[Space cat]

All the doors sufaces have to be painted?

They do in this house.

 

[tim west]

as this is a puzzle i'll presume that just one coat is applied?

 

[Space cat]

i'll presume that just one coat is applied?

Correct.

 

[tim west]

3? 2nd go to put door on its side with painted edges towards walls and floor and the 3rd to repaint the walls after they get messed up.

 

[Space cat]

Nice try but wrong. You will need three sessions just for the door - and a fourth if you mess the walls up! Try it and see.

 

[Soggy_weetabix]

Tried the Rubics cube blind (have you heard the news).

3 minutes to memorise all the moves, but no matter what the positions of each surface was placed in, I can do it in 3 mins.

Aiming for better, and the photographic mind helps. Just read the book in my head.

Dave

Dave

 

[tim west]

Nice try but wrong. You will need three sessions just for the door - and a fourth if you mess the walls up! Try it and see.

for the first go have the door standing up as usual, then lay the door on its side with all painted bits against floor and walls , this exposes the remaining faces to paint

 

[Space cat]

Maybe you misunderstood the rules of this puzzle. You can only have access to three surfaces at any one time: front, right and top. You painted the first three yesterday and it's dried hard enough to touch. The snag is that no combination of twists and turns will put all three remaining surfaces where you can reach them.

There are three ways to turn the door round and each of them will present you with two unpainted surfaces. Odd but true. Try it and see. To get to the third one you would need a reflection and that's something you can't do with a real door. You can see it in a mirror but how do you paint it?

 

[Softus]

How many painting sessions do you need to complete the job?

One.

 

[tim west]

But it does work? after it dries you put the painted face and edges to both the walls and floor leaving the other three unpainted surfaces exposed for painting: bottom edge, other side of door and edge that was previously against the corner wall. The trick is putting the door on its side the second turn.

 

[Space cat]

The trick is putting the door on its side the second turn.

A quarter turn!!! Well done that man. I was wondering when somebody would spot that. In all the years I've been painting doors I've never thought of turning one on its side - mostly because there's never room in this house but that's a pathetic excuse. Go on, say it somebody. WHAT A PLONKER!

 

[Softus]

The trick is putting the door on its side the second turn.

tim is quite right, of course, but, because of the way the question was worded, the answer is still "One".

 

[megawatt]

WHAT A PLONKER

I must admit, I thought it was a trick question and my thinking was the same as Softus's.