puzzle Problem at the Bank

Problem at the Bank

A bank customer had £100 in his account. He then made 6 withdrawals, totaling £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