Workout

Warm-up (600)
100 swim, 100 kick, 100 drill
... 2 rounds 
 
Pre-set (400) 
4 x 100's free on 1:30

Main-set (3 rounds)(2400) 
#1-fly, #2-Breast, #3-back 
Swim, 4 x 75 or 50 on 1:15 
...25 stoke/25 free/25 stroke
Kick, 4 x 75 or 50 on 1:30
...descend 1-2 
Swim, 2 x 100 on 2:00
...no free 

Cool-down 
100 easy choice