Nah, how about 10.
5 races of 5
Three pools, the firsts, seconds and thirds.
The firsts race off
The seconds race off
The thirds race off.
(thats another 3 races)
3 from the 1sts go through, 2 from 2nds and 1 from thirds.
the two seconds and third race off, with two going through.
(one more race)
then the final
(one race)
5+3+1=1=10
