#### Sushi Delight solution

**Answer:**
The probability of removing a piranha in now quite high, much higher
than 50%. The chance is 2/3 or 66.6%. Denote the piranha added to the
bowl as "piranha 2." After removing the piranha from the bowl there are
three equally likely states: piranha 1 in bowl, piranha 2 outside of
bowl; piranha 2 in bowl, piranha 1 outside of bowl; goldfish in bowl,
piranha 2 outside of bowl. In two out of three cases, a piranha
remains in the bowl.

Let me clarify by adding my assumptions: When the
sushi-lover reaches into a bowl containing a piranha and a goldfish,
assume it is equally likely that he will withdraw a piranha as he will
withdraw a goldfish. Also, it's equally likely that the bowl initially
contains a piranha or a goldfish.

If you like statistics, check out the
U. Florida statistics page.

If you like piranha, take a look at
Piranha site.

If you like sushi, take a look at the
California Sushi Academy.