Quote Originally Posted by Pepe n Pilar View Post
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
I will try my very best to answer the puzzle. Hhmmm.

Here is the solution.

1. Lay the boxes out on the floor in order from 1 to 10

2. Take one bar from box 1, 2 bars from box 2, 3 bars from box 3, etc. all the way up to 10 bars from box 10 (55 bars in total)

3. Place all these bars on the scale and press the button to get the total weight.

4.If the total weight shown is 55 lbs and 1 oz, the gold bars are in box 1 (as there is only one bar on the scale that weighs 1 ib and 1 oz)

If the total weight shown is 55 lbs and 2 oz, the gold bars are in box 2 (as there are two bars on the scale that weigh 1 ib and 1 oz)

If the total weight shown is 55 lbs and 3 oz, the gold bars are in box 3 (as there are three bars on the scale that weigh 1 ib and 1 oz)
etc.

In that way you have the idea which case to keep.