Difficulty Level: Easy -- Re: Playing Cards

[Cool Hand]

OK, as a puzzle or riddle, this is really easy, but it is a little tricky. I brought this up on another forum recently, but didn't pose it as a question. It's just a little something I noticed and thought was cool.

Question: Using a standard size, standard face 52-card deck of playing cards in the US, especially those used by Bicycle (the ones Americans are probably most familiar with) or Aviator or any of the other brands made by the US Playing Card Company, how many card faces (not the backs) have an upside down or right side up orientation (vertically -- as in when you rotate them 180 degrees they look different)?

For instance, none of the face cards (K, Q, or J) have a vertical orientation -- they look the same right side up versus upside down. The most obvious example of a card with an orientation is the Ace of Spades (from any deck).

So, out of a 52-card deck, how many in all have a vertical orientation on their face? (Try to answer without Googling or looking at a deck and counting them while doing it -- you can look at a deck casually just to get an idea of what I'm asking, but don't count empirically while looking).

CH

[DrMatt]

Without consulting anything, I get 15:
A,3,5,7,9, x 3 suites.

20 if the diamonds are orientable.

[RCC]

All of them on the deck I use online.

I came up with 15 as well. a/3/5/7/9 sans diamonds

[Mulebear]

Hmmm... Not looking at the cards...

Aces - 3
3s - 3
5s - 3
7s - 4
9s - 3

I get 16...?

[Cool Hand]

Hmmm... Not looking at the cards...

Aces - 3
3s - 3
5s - 3
7s - 4
9s - 3

I get 16...?

Oh, so close. You spotted the fact that the 7 of diamonds is the only diamond that is orientable. Bravo.

The answer is 19. You and the others missed that the 6s x 3 are orientable as well.

Anyway, it's not a trick or anything. I just thought it was an interesting result since most people don't pick up on the 7d. You expect the result to be an even number, but it's not.

CH

[DrMatt]

http://www.google.com/images?um=1&hl=en ... =&gs_rfai=

7 of diamonds orientable?

Sometimes.

[Beleth]

The answer is 19. You and the others missed that the 6s x 3 are orientable as well.

Wouldn't it be 22, then, since the 8s x 3 are likewise orientable?

:8s :8h :8c

[Cool Hand]

From my OP:

Question: Using a standard size, standard face 52-card deck of playing cards in the US, especially those used by Bicycle (the ones Americans are probably most familiar with) or Aviator or any of the other brands made by the US Playing Card Company, ...

Yes, orientable.

CH

[Cool Hand]

The answer is 19. You and the others missed that the 6s x 3 are orientable as well.

Wouldn't it be 22, then, since the 8s x 3 are likewise orientable?

:8s :8h :8c

I don't know what kind of deck those are from, but using a standard size, standard 52-card deck from any of the U.S. Playing Card Company's decks, the 8s are symmetrical, not orientable.

EDIT: At Dr. Matt's link, on Page 3 there is a pic of a blonde girl with a 7 diamonds on her forehead. That's what the ones from the USPCC, like in a Bicycle Standard deck, look like.

CH

[Beleth]

The answer is 19. You and the others missed that the 6s x 3 are orientable as well.

Wouldn't it be 22, then, since the 8s x 3 are likewise orientable?

:8s :8h :8c

I don't know what kind of deck those are from, but using a standard size, standard 52-card deck from any of the U.S. Playing Card Company's decks, the 8s are symmetrical, not orientable.

These are the 8s in question from the Bicycle deck I got at Costco.
Five pips one way, three pips the other.

[Cool Hand]

The answer is 19. You and the others missed that the 6s x 3 are orientable as well.

Wouldn't it be 22, then, since the 8s x 3 are likewise orientable?

:8s :8h :8c

These are the 8s in question from the Bicycle deck I got at Costco.
Five pips one way, three pips the other.

Oops. You, sir, are correct. I was wrong. The 8s x 3 are indeed orientable, so your answer of 22 is right, and my answer of 19 was wrong. D'oh.

I apologize. Good eyes and good catch. You win the thread.

CH

EDIT: the new forum software gave an error message that said you may embed only three layers of quotes, so I had to remove some to make this post; I was not trying to edit so as to remove my incorrect statement from above or your correct observation. Beleth still wins the thread.

[Cool Hand]

I guess it wasn't so easy after all. I FAIL in the puzzles and games forum.

CH

[Beleth]

No no! It was an awesome puzzle. It just happened to be about something that caught my eye when I was about 9 years old, and only now resurfaced.

Thank you for posting it!

[whitefork]

so why aren't the 7s printed with the suit the center like the 9s are? I see a couple of examples where the 9s are asymetrical but not in the decks you cite.