I shamelessly stole this puzzle from another website
Category Puzzle Numbers
I stole this puzzle from another website, I liked it and thought the people that typically read this blog would like it too. Here it is:
A friend of mine has £100 in a bank account. Whenever he takes out money he records how much he has taken out and the balance. Here are his accounts for last week….
There is one small problem – the WITHDRAWN column adds up to 100, but the BALANCE column adds up to 101 – how can this be the case?
I stole this puzzle from another website, I liked it and thought the people that typically read this blog would like it too. Here it is:
A friend of mine has £100 in a bank account. Whenever he takes out money he records how much he has taken out and the balance. Here are his accounts for last week….
Withdrawn | Balance |
40 | 60 |
30 | 30 |
20 | 10 |
9 | 1 |
1 | 0 |
There is one small problem – the WITHDRAWN column adds up to 100, but the BALANCE column adds up to 101 – how can this be the case?
Comments
Posted by Rob McDonagh At 08:56:14 PM On 06/14/2011 | - Website - |
Now for the complete geekery...
Let the left column be represented by a + b + c + d + e = 100
The right column is (100-a)+(100-(a+b))+(100-(a+b+c))+(100-(a+b+c+d))+(100-(a+b+c+d+e))
The last term of the that expression is zero, so the right column simplifies to (100-a)+(100-(a+b))+(100-(a+b+c))+(100-(a+b+c+d))
That rearranges to 400-4a-3b-2c-d
Notice that at this point everything is completely independent of the actual values of a, b, c, d and e. You can pick any values, as long as they sum to less than 100. So pick 1, 1, 1, 1 and 96. In that case, the right column comes would sum up to 390. That's the maximum value you could find there.
Posted by Richard Schwartz At 09:29:44 PM On 06/14/2011 | - Website - |
Posted by Richard Schwartz At 10:08:14 PM On 06/14/2011 | - Website - |
Similar but harder to figure out.
Three guests check into a hotel room. The clerk says the bill is $30, so each guest pays $10. Later the clerk realizes the bill should only be $25. To rectify this, he gives the bellhop $5 to return to the guests. On the way to the room, the bellhop realizes that he cannot divide the money equally. As the guests didn't know the total of the revised bill, the bellhop decides to just give each guest $1 and keep $2 for himself.
Now that each of the guests has been given $1 back, each has paid $9, bringing the total paid to $27. The bellhop has $2. If the guests originally handed over $30, what happened to the remaining $1?
Posted by Hynek Kobelka At 11:02:43 AM On 06/15/2011 | - Website - |
Posted by Carl Tyler At 11:08:47 AM On 06/15/2011 | - Website - |