Can you please show me how to solve this?
A man was given eight pound coins. howerver, one of them was fake and he did not know if the fake coin weight more or less than the other coin. what is the minimum number of weighings that it would take to guarantee him finding the counterfeit coin? Assume a balance scale is used.
Divide them into two … weigh … (1) 8 coins in play
Take the lighter one …
Divide them into two …. weigh (2) 4 coins in play
Take the lighter one
Divide them into two … weigh (3) 2 coins in play …
You found it ………….!!
64
2, one to find the differnece, and one to test on another coin, to tell which coin was fake
2 …..sure
mark them ABCDEFGH
put the ABC DEF FGH on the two sides of balance scale
you will find the special group( assume ABC cant balance
with DEFand FGH )it cost 2 step
Assume the ABC contain the fake coin .it cost 2 step,too
Then follow the first step you can find the fake coin.
all cost 4 steps
may be it’s not the minimum
(the fake coin weight more or less than the other coin.
we cant find the fake one by it’s lighter than other group)
So it’s not 2 steps