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assuming that she knows binary code i would think she converts the head and number to 0 and 1. now she toss the coin 2 times. she can get 00, 01, 10, and 11. 00 - first dress 01 - second dre

If you’re 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?   SOLVED   Click on the spoiler below

One of the person, is the genitor (sperm donation) of the daughter and it's the day of the first meeting between Dad and mom.

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Answer is 100 (if we assume that the images of green apples in equation 2 & 3 = 2 apples, instead of 1.5).

Spoiler

 

Equation 1: 3x = 90 => x = 30 (Red Apple = 30)

Equation 2: x + 2y + 2y = 230 => 4y = 200 => y = 50 (Green Apple = 50)

Equation 3: z + 2y + x = 210 => z + 100 + 30 = 210 => z = 80 (Yellow Apple = 80)

Equation 4: y - x + z = A => 50 - 30 + 80 => A = 100

 

 

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A woman needs a new dress and so she enters a store. Upon trying many dresses, she likes 3 of them the most. She can't decide between the 3 and ends up leaving it to luck, so she reaches for her purse and takes out a single coin.

Using that coin only, how can she pick a dress randomly while being fair (equal probability for each of the 3 choices)?

Good luck!

 

SOLVED

 

Click on the spoiler below to reveal the correct answer.

Spoiler

Started with the common purpose that we need to choose a dress using toss (yes/no) for each dress :

Positive way (we find a direct tree to the goal) :

3 (from) > 3 (yes) > 2 (yes) > 1(yes)

or gives :

3 > 1 (means 2 no at first shot)

or gives :

3 > 2  > 1

So 9 moves for a first direct approach to the goal, that we can x3 to let a chance to each entity to get its tree ^^ = 27 moves for something fair (let's close the eyes and take one dress randomly, it's easier ^^)

 

Alternative way:

Assuming that she knows binary code i would think she converts the head and number to 0 and 1. now she toss the coin 2 times. she can get 00, 01, 10, and 11.

00 - first dress

01 - second dress

10 - third dress

11 - try again

thats equal chance for each - 25%

 

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7 hours ago, JillyJill said:

I think we could use a little hint. Does she actually throw this coin or does something else with it?

When there's "luck", "coin" and "probability" in the same context, then yes, it's almost always assumed that there's a coin toss. So you're completely right. :)

The above is not a hint though, so I'll provide one below:

Spoiler

As we know, a coin has only 2 sides. A single coin toss can only represent 2 outcomes (example: Heads = Dress1, Tails = Dress2). Pay attention to the word in bold. :)

 

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Started with the common purpose that we need to choose a dress using toss (yes/no) for each dress :

Positive way (we find a direct tree to the goal) :

3 (from) > 3 (yes) > 2 (yes) > 1(yes)

or gives :

3 > 1 (means 2 no at first shot)

or gives :

3 > 2  > 1

So 9 moves for a first direct approach to the goal, that we can x3 to let a chance to each entity to get its tree ^^ = 27 moves for something fair (let's close the eyes and take one dress randomly, it's easier ^^)

First intention, be clement pls :D

ps: *see > as a toss*

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@Substanz You're correct! I didn't expect that solution also.

@Teddy Your reasoning(binary code) while not right, happens to make your execution both completely correct and optimal(lowest number of tosses while 100% fair)!

You're both technically correct with both answers having their pros and cons. Apologies, but I can't choose a winner, I leave it up to you.

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