What do you think?

LipstickLola · 10-15-2010, 04:06 PM

This might as well be the "one train leaves the NY station at 10 am doing 100 mph, one train leaves Chicago at 10 am doing 150 mph, what time do they intersect in.....Timbucktoo?"

theoddz · 10-15-2010, 04:44 PM

Ooooo.....I love love LOVE these kinds of problems!!!!

Wish I'd gotten in on this one a bit sooner.

~Theo~

.....loves puzzles and problem-solving exercises.

rlin · 10-15-2010, 05:19 PM

i imagine that halving them til you get to the winner is the better idea... if the scale has to be used and they are identical i believe that would be the best bet...
of course... i am sure that there must be something else that works better... because that just sounds too logical and easy...

Soft*Silver · 10-15-2010, 05:28 PM

Take 1 known genuine coin by weight. Divide the rest into 3 of 33 and weight them. The pile that is lighter or heavier gets cut into 3rds till you single it out.

JAGG · 10-15-2010, 05:39 PM

Well the question is ambiguous .If you have to pay each time you use the scale, does putting them on and then off count as one time or two? Also if you have to pay everytime you use the scale what's the goal here, what's the object of this quest? To spend the least amount of money possible in your quest, or is the goal to find out which coin is bogus? Anyway I have about 20 more questions because your details are not very clear. But here's my answer. Assumming putting all the coins on the scale counts as a one time use , and taking them all off counts as an additional use, I'd put all the coins on the scale. ( that's one time) Then I'd take them off one at a time, watching the scale for the difference in weights. (For example the first 15 I took off, all weighted 3 ounces each but the 16th one weighted 2 ounces, and the next 4 I took off weighted 3 ounces, I'd set the one that weightes 2 ounces aside) I'd set the different one aside and finished taking the other coins off, that would count as the second use of the scale. So 2 times I'd use the scale. If putting them on and off counts as one time use then I only used the scale once.

Gemme · 10-15-2010, 05:59 PM

Math is hard.

I'd bring them all to a coin dealer and let him or her sort it out.

Soft*Silver · 10-15-2010, 06:24 PM

nooooo... you have to use that scale!

Quote:

Originally Posted by Gemme

Math is hard.

I'd bring them all to a coin dealer and let him or her sort it out.

Gemme · 10-15-2010, 06:29 PM

Quote:

Originally Posted by softness

nooooo... you have to use that scale!

Make me.

*grin*

This is not my forte but I am interested in the best answer.

Chancie · 10-15-2010, 07:13 PM

Quote:

Originally Posted by JAGG

Well the question is ambiguous .If you have to pay each time you use the scale, does putting them on and then off count as one time or two? Also if you have to pay everytime you use the scale what's the goal here, what's the object of this quest? To spend the least amount of money possible in your quest, or is the goal to find out which coin is bogus? Anyway I have about 20 more questions because your details are not very clear. But here's my answer. Assumming putting all the coins on the scale counts as a one time use , and taking them all off counts as an additional use, I'd put all the coins on the scale. ( that's one time) Then I'd take them off one at a time, watching the scale for the difference in weights. (For example the first 15 I took off, all weighted 3 ounces each but the 16th one weighted 2 ounces, and the next 4 I took off weighted 3 ounces, I'd set the one that weightes 2 ounces aside) I'd set the different one aside and finished taking the other coins off, that would count as the second use of the scale. So 2 times I'd use the scale. If putting them on and off counts as one time use then I only used the scale once.

It's a balance scale, so you can compare coins in groups or singly.

And the idea is to be efficient.

Chancie · 10-17-2010, 11:08 AM

There are a few different ways to start this problem.

My students agreed that

They would divide the coins in four piles with 25 coins each, and

I labeled them A, B, C, and D.

First we compared A and B, and either

They balanced the scale, which meant that they were all valuable coins or

They were different, which meant that all the coins in C and D were genuine.

Gemme · 10-18-2010, 09:40 PM

Yay for Dreamer being the closest.

homoe · 04-26-2021, 03:42 PM

Quote:

Originally Posted by LipstickLola

This might as well be the "one train leaves the NY station at 10 am doing 100 mph, one train leaves Chicago at 10 am doing 150 mph, what time do they intersect in.....Timbucktoo?"

I have NO idea but if it's safe to travel you can bet I'd be on that damn train!

10-15-2010, 04:06 PM	#1
LipstickLola Member How Do You Identify?: Happy Preferred Pronoun?: she Join Date: Sep 2010 Location: planet Earth Posts: 682 My Photo Gallery Thanks: 1,679 Thanked 1,597 Times in 433 Posts Rep Power: 5678218	This might as well be the "one train leaves the NY station at 10 am doing 100 mph, one train leaves Chicago at 10 am doing 150 mph, what time do they intersect in.....Timbucktoo?" __________________ Happiness......it's a choice!!

10-15-2010, 04:44 PM	#2
theoddz Senior Member How Do You Identify?: Cranky Old Poop Preferred Pronoun?: Mr. Beast Relationship Status: Married to a beautiful babe whom I don't deserve. Join Date: Nov 2009 Location: Central Texas Posts: 3,547 My Photo Gallery Thanks: 11,163 Thanked 9,942 Times in 2,518 Posts Rep Power: 21474856	Ooooo.....I love love LOVE these kinds of problems!!!! Wish I'd gotten in on this one a bit sooner. *~Theo~* .....loves puzzles and problem-solving exercises. __________________ *"All that is gold does not glitter, Not all those who wander are lost; The old that is strong does not wither, Deep roots are not reached by the frost."* -- J. R. R. Tolkien

10-15-2010, 05:28 PM	#4
SoftSilver Infamous Member How Do You Identify?: femme Preferred Pronoun?: she Relationship Status: Married Join Date: Nov 2009 Location: rose cottage Posts: 5,594 My Photo Gallery Thanks: 8,948 Thanked 15,896 Times in 4,064 Posts Rep Power*: 21474858	Take 1 known genuine coin by weight. Divide the rest into 3 of 33 and weight them. The pile that is lighter or heavier gets cut into 3rds till you single it out. __________________ Pole bachit, a lis chuye. The field sees, the forest hears

10-15-2010, 05:39 PM	#5
JAGG Infamous Member How Do You Identify?: Butch Preferred Pronoun?: JAGG Relationship Status: =) Join Date: Nov 2009 Location: Tulsa (cat free zone) Posts: 6,093 My Photo Gallery Thanks: 18,651 Thanked 17,528 Times in 4,137 Posts Rep Power: 21474859	Well the question is ambiguous .If you have to pay each time you use the scale, does putting them on and then off count as one time or two? Also if you have to pay everytime you use the scale what's the goal here, what's the object of this quest? To spend the least amount of money possible in your quest, or is the goal to find out which coin is bogus? Anyway I have about 20 more questions because your details are not very clear. But here's my answer. Assumming putting all the coins on the scale counts as a one time use , and taking them all off counts as an additional use, I'd put all the coins on the scale. ( that's one time) Then I'd take them off one at a time, watching the scale for the difference in weights. (For example the first 15 I took off, all weighted 3 ounces each but the 16th one weighted 2 ounces, and the next 4 I took off weighted 3 ounces, I'd set the one that weightes 2 ounces aside) I'd set the different one aside and finished taking the other coins off, that would count as the second use of the scale. So 2 times I'd use the scale. If putting them on and off counts as one time use then I only used the scale once. __________________ I don't want to spend my life with someone I can live with, I want to spend my life with someone I can't live without.

10-15-2010, 05:59 PM	#6
Gemme Practically Lives Here How Do You Identify?: Queer Stone Femme Girl of the Unicorn Variety Preferred Pronoun?: She, as in 'She's a GEM' Join Date: Nov 2009 Location: The roads are narrow here Posts: 36,631 My Photo Gallery Thanks: 182,498 Thanked 107,907 Times in 25,665 Posts Rep Power: 21474889	Math is hard. I'd bring them all to a coin dealer and let him or her sort it out. __________________ Gemme's Journal I'm misunderestimated.

10-15-2010, 05:19 PM	#3
rlin Member How Do You Identify?: human Join Date: Mar 2010 Location: nomad Posts: 712 My Photo Gallery Thanks: 1,450 Thanked 1,189 Times in 451 Posts Rep Power: 1004849	i imagine that halving them til you get to the winner is the better idea... if the scale has to be used and they are identical i believe that would be the best bet... of course... i am sure that there must be something else that works better... because that just sounds too logical and easy...

10-17-2010, 11:08 AM	#10
Chancie Senior Member How Do You Identify?: queer femme-inist Relationship Status: I'm lucky. Join Date: May 2010 Location: Western Mass Posts: 3,774 My Photo Gallery Thanks: 9,518 Thanked 14,540 Times in 2,744 Posts Rep Power: 21474855	There are a few different ways to start this problem. My students agreed that They would divide the coins in four piles with 25 coins each, and I labeled them A, B, C, and D. First we compared A and B, and either They balanced the scale, which meant that they were all valuable coins or They were different, which meant that all the coins in C and D were genuine.

10-18-2010, 09:40 PM	#11
Gemme Practically Lives Here How Do You Identify?: Queer Stone Femme Girl of the Unicorn Variety Preferred Pronoun?: She, as in 'She's a GEM' Join Date: Nov 2009 Location: The roads are narrow here Posts: 36,631 My Photo Gallery Thanks: 182,498 Thanked 107,907 Times in 25,665 Posts Rep Power: 21474889	Yay for Dreamer being the closest. __________________ Gemme's Journal I'm misunderestimated.

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