+870 Here are a few problems for you; they are not extremely hard to solve, but it may take a few time anyway to resolve them.
Problem number 1: Imagine you are given two barrels, one with a capacity of 5 L, and the other with a capacity of 3 L.
Given that the barrels ain't graduated, can you manage to put exactly 4 L in the largest barrel?
N.B.: You may completely fill and empty the two barrels as many times as you want, and decant the content of one in the other.
Problem number 2: A thiefs breaks into a museum and steals nine jewels; but he knows that only one of them is a real one, the eight other ones being fake. He only knows that the real jewel is slightly heavier than the others, but he only has a Roberval balance, meaning he can't get the exact masses of the jewels.
In only two weighings, can he find the real one?
Problem number 3: What is thirty divided by a half plus twenty?
Problem number 4: With six identical matches, can you make exactly four triangles?
Good luck!
N.B.: I think marking the work is useless, so I won't mark these questions. Anyway, if you get them all right, you still earn a brownie!
#1 Fill 5 then fill 3 from it leaving two in 5 dump 3 and puor the reaming two into it Fill five again then pour from it to fill 3 (it will only take one gallon since it already has two in it)...that will leave 4 gal in the 5 gal barrel
+870 That's correct Guest!
Since I think there won't be one person who answer all four questions, I'll give a cookie to everyone who has reolved one or more of the problems when the four are solved.
+129899 Problem 2
Put 3 jewels on one side and 3 on the other :
1st scenario - they balance
Take them all off
Pick any two of the remaining three jewels
Put them on the scale.....if they balance....the remaining one is the real one
If they don't balance......the real one has to be the heavier
Result......real one is found after just two weighings
2nd scenario - they don't balance and one side is heavier
Take the three jewels from the heavier side
Pick any two of these
Put them on the scale.....if they balance....the remaining one is the real one
If they don't balance......the real one has to be the heavier
Result......real one is found after just two weighings
+5265 Lets see... You said only using six matchsticks. You never said I couldn't break them apart! e.e Break the matchsticks until you have 12 pieces and make 4 triangles.
+870 CPhill, your answer is correct; one to go!
Melody, you're right, breaking the matches isn't allowed (but 3D is allowed; I just gave you all a huge hint!)
+870 That's right rarinstraw1195; here is a triangular pyramid (or a tetrahedron; let's call a spade a spade):
Congratulations to Hayley1, Guest, CPhill and rarinstraw1195 for solving those problems; you each deserve a brownie!
Yum...
