Privacy Policy + T&C

We use cookies to personalise our content and ads, and for traffic analysis. Information is also
shared with our advertising and analytics providers. By using the site you also agree to our T&C.


Common Answers

Have you entered July's Common Answers?

BB Logo Spacer

Puzzle - Answer

A bank customer had $100 in his account. He then made 6 withdrawals, totalling $100. He kept a record of these withdrawals, and the balance remaining in the account, as follows:

Withdrawals     Balance left
     $50             $50
      25              25
      10              15
       8               7
       5               2
       2               0
     ---             ---
    $100             $99

When he added up the columns as above, he assumed that he must owe $1 to the bank. Was he right?

 [Ref: ZEZC]

There is no reason whatever why the customer's original deposit of $100 should equal the total of the balances left after each withdrawal. The total of withdrawals in the left-hand column must always equal $100, but it is purely a coincidence that the total of the right-hand column is close to $100. For example:

Withdrawals     Balance left
      $5             $95
      10              85
      85               0
     ---             ---
   $100             $180

Back to the puzzles...



This website uses cookies, for more information please view our privacy policy. By using the site you also agree to our terms and conditions.