You guys deserve some R&R...

[Gan]

So here's a random riddle:

A kid passes a guy which says hey to him. Later the Kid goes back in time to when that guy was younger and says hey to him.

Who knew who first?


-Gan

[WarHampster]

Is it significant that you capitalized 'kid' the second time? Or that you used 'which' instead of 'who'?

[Gan]

Nope, neither are significant. This is coming to you from an iPhone.


-Gan

[Silverwind]

Hmm... if they were both strangers, I reckon they met at the same time?

What about that old school riddle: "A man weighs 100 pounds plus half his weight. How much does he weigh?"

I was totally stumped at the answer, but eventually I realised why I was stumped.

[GMG Hendo]

Hmm... if they were both strangers, I reckon they met at the same time?

What about that old school riddle: "A man weighs 100 pounds plus half his weight. How much does he weigh?"

I was totally stumped at the answer, but eventually I realised why I was stumped.

Hehe I can see many people thinking "easy, 150" but really it doesn't specify how much he weighs. It's just saying he weighs 100+(weight/2)

weight never specified though

[Gan]

Hmm... if they were both strangers, I reckon they met at the same time?

They met two times at the same time in different times. Who knew who first though?


-Gan

[Mystor]

Hehe I can see many people thinking "easy, 150" but really it doesn't specify how much he weighs. It's just saying he weighs 100+(weight/2)

weight never specified though

let w be the weight

w = 100 lb + 0.5w
.5w = 100 lb
w = 200 lb

Therefore the weight of the person is 200 pounds.

YAY FOR GR. 7 ALGEBRA

[Silverwind]

They met two times at the same time in different times. Who knew who first though?

I think that they're one and the same person.

let w be the weight

w = 100 lb + 0.5w
.5w = 100 lb
w = 200 lb

Therefore the weight of the person is 200 pounds.

YAY FOR GR. 7 ALGEBRA

That's the traditional answer, but I've never understood it. As Hendo pointed out, the initial weight of the person isn't defined, so adding 100 to it is meaningless.

[Gan]

I understand that. Just put it in math form.


-Gan

[GMG Hendo]

let w be the weight

w = 100 lb + 0.5w
.5w = 100 lb
w = 200 lb

Therefore the weight of the person is 200 pounds.

YAY FOR GR. 7 ALGEBRA

weight = 100+(0.5*weight)

due to the laws of BEDMAS you'd have to multiply 0.5*weight first in this equation. Since weight is undefined your answer is not correct.

[Gan]

I believe Mystron was correct. Subtract w by .5w. Then continue.


-Gan

[Silverwind]

But I still don't get it. How are you determining what half the man's weight is before adding 100 to it? I'm pretty simple minded, but the traditional answer (Mist's equation) looks wrong to me. I mustn't be adding things up in the correct order or something, because this is the way I see it:

weight = undefined
halfOfWeight = weight / 2
weight = weight + halfOfWeight
weight = weight + 100

What am I doing wrong?

[Gan]

Weight isn't undefined, just unknown.
In the equation there is only 1 variable. That is weight. HalfOfWeight needs to be .5w. Which is half of w. So just do some simple algebra.


-Gan

[Silverwind]

But, I still don't get it. The man's weight is unknown/undefined to begin with, so after adding 100 to it couldn't you end up with any value above 100? What exactly are you assuming his initial weight to be before adding 100 to it?

Please! PLEASE!!! I must know!

[Gnome]

100 plus half his weight is the total weight.

2 halfs make a whole. therefore, 100 is half is weight.

.5w + (.5w) = w

and obviously. .5w = .5w

and we know already that .5w = 100

100 + 100 = w

200 = w



Hope that helps.