[southlight]

Originally Posted by AMERICUS

BUT 3 * 9 = 27 + 2 = 29...

Like mentioned before it's more a trick than broken math. The story suggests your equation above, but that equation doesn't need to be solved. Another way to tell that this equation doesn't need to work is to split it up to its single values:

27 + 2 = 29
(25 + 2) + 2 = 29

In the last line you see that you factor the 2 $ tip in twice. Why would a equation containing the 2 $ tip twice need to make sense? It doesn't need to. Hope this helps.

Originally Posted by E90 87ss

Each pay $10 = $30

Their change is $5

All three pay $25 or the cost of the room, 25/3 = $8.33 per person...

They each receive a dollar back, so $9.33 per person...

9.33x3= 27.99 and they leave a $2 dollar tip, so $29.999999999999999...

What's the lol about???

Yep, another way to come to the same conclusion, just backwards calculated.


Best regards,
south

[southlight]

Originally Posted by Optherion

Anyways reminds me of an old one, Here goes:

You have a bag of 20 marbles, 10 are Red and 10 are blue. You reach into the bag and pick a marble without looking. You repeat this 10 times. Of the 10 times you reach into the bag, you pull out a blue marble 6 times, and a red marble 4 times. What are the odds the next marble will be blue?

You beat me to it. Anyways, 40%.


Best regards,
south

[AMERICUS]

Tip is not factored twice. Each person paid $10 and each was given $1 back. So each person paid $9. $9 * 3 people = $27 + $2 (tip) = $29.

But it works out fine if the manager originally has the $30, gives back $3 and keeps $2 for the tip.

Originally Posted by southlight

Like mentioned before it's more a trick than broken math. The story suggests your equation above, but that equation doesn't need to be solved. Another way to tell that this equation doesn't need to work is to split it up to its single values:

27 + 2 = 29
(25 + 2) + 2 = 29

In the last line you see that you factor the 2 $ tip in twice. Why would a equation containing the 2 $ tip twice need to make sense? It doesn't need to. Hope this helps.


Yep, another way to come to the same conclusion, just backwards calculated.


Best regards,
south

[southlight]

Originally Posted by AMERICUS

Tip is not factored twice. Each person paid $10 and each was given $1 back. So each person paid $9. $9 * 3 people = $27 + $2 (tip) = $29.

But it works out fine if the manager originally has the $30, gives back $3 and keeps $2 for the tip.

Each person paid $9 including the $1 tip, hence the tip would be factored twice in that equation. So, it works out fine either way.


Best regards,
south

[m2kev]

Originally Posted by AMERICUS

Tip is not factored twice. Each person paid $10 and each was given $1 back. So each person paid $9. $9 * 3 people = $27 + $2 (tip) = $29.

But it works out fine if the manager originally has the $30, gives back $3 and keeps $2 for the tip.

9 * 3 = $27.00 you're right, but + $2.00 tip again? $25 is the original price of the hotel, $25.00 + $2.00 tip = $27.00

And your saying add another $2.00 tip = $29.00... don't make sense lol, so obviously $3.00 is missing (which is what each person got back in return $1.00 each x 3 = $3.00)

[scorcherjf]

Originally Posted by Optherion

Anyways reminds me of an old one, Here goes:

You have a bag of 20 marbles, 10 are Red and 10 are blue. You reach into the bag and pick a marble without looking. You repeat this 10 times. Of the 10 times you reach into the bag, you pull out a blue marble 6 times, and a red marble 4 times. What are the odds the next marble will be blue?

I don't get why this one is tricky?

[Hawkeye]

Originally Posted by Optherion

Anyways reminds me of an old one, Here goes:

You have a bag of 20 marbles, 10 are Red and 10 are blue. You reach into the bag and pick a marble without looking. You repeat this 10 times. Of the 10 times you reach into the bag, you pull out a blue marble 6 times, and a red marble 4 times. What are the odds the next marble will be blue?

Originally Posted by southlight

You beat me to it. Anyways, 40%.


Best regards,
south

Not necessarily. If the marbles are replaced instead of kept out it is still just 50%.

[Optherion]

Originally Posted by Hawkeye

Not necessarily. If the marbles are replaced instead of kept out it is still just 50%.

correct it is always 50 percent when replaced. You would be surprised how many people things your odds change when flipping a coin a certain amount of times It will always be 50/50

[radix]

Originally Posted by Optherion

correct it is always 50 percent when replaced. You would be surprised how many people things your odds change when flipping a coin a certain amount of times It will always be 50/50

The odds do change as you flip the coin, in a way. While the odds of selection of any one independent flip remain 0.5, they diminish exponentially with each successive successful selection. In other words, they are 0.5^n where n represents the number of consecutive heads or tails. Put another way, the probability of getting heads 10 times in a row is 0.5^10 or 0.0009765625.

[southlight]

Originally Posted by Optherion

correct it is always 50 percent when replaced.

Well, that depends on the understanding of "You repeat this 10 times". Okay, you tricked me.


Best regards,
south

[Spool]

Okay i'm Asian, i was born with an abacus in my hand so let me explain...when you encounter a group problem such as this....calculate everything as a whole transaction rather than each individual to avoid confusion.

Let's just say me and my 2 friends pool our money together for the hotel room for a gang bang...well it was only 25 bucks so our group gets 5 dollar back...BUT, let's just leave that 5 bucks aside for now..and come to realize that the 25 bucks we put in was 8.33 cents from each of us...and then we take back another dollar each so that makes it more than 9.33 dollars...per person...times 3 is 28..and the 2 dollars we gave the concierge makes it an even 30...there is no missing dollar, or other confusion...you just have to look at it as a whole transaction and not individual ones.

[jhv]

Originally Posted by Spool

Okay i'm Asian, i was born with an abacus in my hand so let me explain...when you encounter a group problem such as this....calculate everything as a whole transaction rather than each individual to avoid confusion.

Let's just say me and my 2 friends pool our money together for the hotel room for a gang bang...well it was only 25 bucks so our group gets 5 dollar back...BUT, let's just leave that 5 bucks aside for now..and come to realize that the 25 bucks we put in was 8.33 cents from each of us...and then we take back another dollar each so that makes it more than 9.33 dollars...per person...times 3 is 28..and the 2 dollars we gave the concierge makes it an even 30...there is no missing dollar, or other confusion...you just have to look at it as a whole transaction and not individual ones.

9.33*3 =/= 28 flat

[Optherion]

Originally Posted by radix

The odds do change as you flip the coin, in a way. While the odds of selection of any one independent flip remain 0.5, they diminish exponentially with each successive successful selection. In other words, they are 0.5^n where n represents the number of consecutive heads or tails. Put another way, the probability of getting heads 10 times in a row is 0.5^10 or 0.0009765625.

Whoa man lets not look at it too hard, this was off my 3rd grade nephews homework last week when I was watching him. For the sake of most the world, the odds when flipping a coin are 50/50

But yes that would make sense, consecutively the odds of anything happening repeatedly diminish exponentially.