we have 7 coins , 6 coins are in equal weight and 1 different how we find that coin using weighing machine.?

Answer 1

Out of the 7 coins take any 6 coins and place 3 coins on each side of the physical balance. If both the sides weigh equally then we know that the remaining one is the one with the different weight.
If the balance is inequal then take the first set of 3 coins and weigh each one with each other one. In this method if we obtain equilibrium with two coins one on each side then the remaining one is the one with the inequal weight.
If all the 3 have the same weight then take the next set of three coins and apply the same procedure to obtain the coin with inequal weight.

Answer 2

If we know that the different coin is heavier than the others, we can figure out which coin it is using the scale twice.

For the first weighing, put two of the coins on one platter, two on the other, and leave three off.
* If one of the sides weighs more than the other, the different coin is on that side; now just use the scale again to compare the two coins from that side.
* If both sides weigh the same on that first weighing, then one of the remaining three coins is the different one. Of those three, put one coin on one platter, another on the other platter, and leave the third off. The different coin will be the heavier of the two on the scale, or the leftover coin, if both platters are equal in weight again.

If we know the different coin is lighter, the process is more or less the same.

If we don't know whether the different coin is heavier or lighter, but just that it's different in weight, we'll need more than two weighings.

Start the same way: put two coins on one platter, two on the other, and leave three off.
* If the two sides have different weights, then remove one coin from each side.
**If the two sides are still unbalanced, then replace the coin on one platter with one of the other coins. If the two sides are now balanced, the one you took off the platter is the different one; if they're still unbalanced, it's the one you *didn't* remove.
**If the two sides balanced after you removed one coin from each side, then one of the two coins you removed is the culprit. Replace the coin on one of the platters with one of the two you just removed; if the scale still balances, it's the other one you removed, but if it goes off-balance, it's the one you just put on the platter.

*On the other hand, if, when you weighed the four coins to start with, the scale was balanced, one of the remaining three coins is the culprit. Use two more weighings to compare those three coins in pairs; the one that causes the imbalance is the culprit.

So, if you don't know whether the different coin is heavier or lighter, you can still figure it out in only three weighings. If you know it's heavier (or lighter), you can do it in two.

Hope that helps!

Answer 3

coins 1,2,3,4,5,6,7

1,2,3 : 4,5,6

if both of these are equal, then the coin that was left out was the one that was different, if not then

1,2,3 : 4,5,6

take the side that is either heavier or lighter, depending if the 1 different coin is suppose to be lighter or heavier, and you get

1 : 2 with 3 left out

if 1 and 2 are equal, then 3 is the different coin, if not, then either 1 or 2 is the different coin.

Answer 4

measure each coins weight 1 by 1
this is obvious

Answer 5

YOUR QUESTION IS NOT COMPLETE I HAVE HEARD IT BE4 YOU COULD ADD HOW MANY CHANCE DO WE HAVE TO WEIGH.
NOW DIVED THE COINS INTO TWO OF THREE,YOU REMAIN WITH ONE BALANCE THE SIX THREE ,THREE IF THEY BALANCE YOU KNOW THE REMAINING IS THE ONE IF NOT YOU GO FORTHE HEAVY PART.TAKE THE THREE AND DIVED AGAIN AND DO THE SAME.
TRY NOW

Answer 6

if we know the odd coin is heavier or light... it will take a maximum of two trials...

Answer 7

Your question is incomplete u also have to mention the number of times we are a;llowed to use the scale.