Tina is a professional boxer.  She wins her first 10 fights of her career.  She then goes on to win 5 more before losing her first fight, and then doubles her number of wins before losing again.  She then retires.  How many more wins than losses does she have at the end of her career?
Tina wins her first 10, and then wins 5 more for 10+5 = 15 wins before losing 1.
She then doubles her number of wins for a total of 15*2=30 wins, before losing 1 more for 1+1=2 losses.
For her career she has 30-2=<<30-2=28>>28 more wins than losses.
#### 28