Kaplan & NG feeds

quick question as i am reviewing for nclex-rn. there are a few questions... which one needs further teaching & i keep getting tripped up on the give a large amount of ng feed over 30 min or 45 min. what is the maximum amount of feeds that can be given in 30 min & in one hour without producing some kind of dumping syndrome??? its not in my kaplan book & i cannot find it online.. any help?