Jasper raises his kite at a rate of 240 feet in 12 minutes, or 240/12=<<240/12=20>>20 feet per minute.
Jasper raises his kite at three times the speed Omar does, or 3*20=<<3*20=60>>60 feet per minute.
To raise his kite 600 feet, it will take Jasper 600/60=<<600/60=10>>10 minutes.
#### 10