Anybody fancy doing a puzzle???

[GaryFifer]

You guys are obviously too good at the basic maths puzzles. Hope this one will keep you busy for a bit longer.

Here is the problem.

•You are in a room with 10 cases, each containing 20 metal bars.
•Nine of the cases contain bars of worthless base metal that looks like gold and one case contains bars of solid gold.
•You know that each bar of base metal weighs exactly 1 pound and each gold bar weighs one pound and one ounce.
•There is an electronic scale in the room, but it can only be used once and will flash the weight for only 5 seconds.
•You have no other equipment.
•You may leave the room with one case, which is yours to keep.
•How do you pick the right case?

Remember, you are looking for a mathematical solution so no questions please about whether the bars are painted, or feel different, or if there is a way to use the scales more than once, etc.

Good luck.

Mr P&P

See you imperial oldies! We are metric now so I had to check up!

If X = 1 pound thats 16 oz (because 16 oz in 1 pounds)
Y= 1.1 pound thats 17 oz

1 case of metal= 20 x 16= 320 oz /16= 20 pounds
1 case of gold =20 x 17 = 340 oz/16 = 21.25 pounds (or 21lbs 4oz)

I would organise the boxes in a row. then take 1 bar out of each boxes and weigh individually as quick as possible!? But i am thinking you cannot do that in 5 seconds..

You take any bar out of a box and put on scale and keep looking for a 1.1 on the scale! But if u did not have time.

[Pepe n Pilar]

See you imperial oldies! We are metric now so I had to check up!

If X = 1 pound thats 16 oz (because 16 oz in 1 pounds)
Y= 1.1 pound thats 17 oz

1 case of metal= 20 x 16= 320 oz /16= 20 pounds
1 case of gold =20 x 17 = 340 oz/16 = 21.25 pounds (or 21lbs 4oz)

I would organise the boxes in a row. then take 1 bar out of each boxes and weigh individually as quick as possible!? But i am thinking you cannot do that in 5 seconds..

You take any bar out of a box and put on scale and keep looking for a 1.1 on the scale! But if u did not have time.

You are definitely on the right lines, but you are correct when you say you wouldn't have time. Just need to think outside the box a tiny bit more.