Question id 637 - Aircraft General Knowledge - Airframe, Systems, Powerplant - ATPL - Airline Transport Pilot license

Twin spool or triple spool jet engines require a high by pass ratio.
At high subsonic airspeeds they have a better propulsive efficiency than propeller or straight jet engines.
They are lighter than straight jet engines.
They produce less noise.

Training tests and timed exam simulations ATPL - Airline Transport Pilot license