All trainees in a certain aviator training program must take both a written test and a flight test. If 70 percent of the trainees passed the written test, and 80 percent of the trainees passed the flight test, what percent of the trainees passed both tests?
(1) 10 percent of the trainees did not pass either test.
(2) 20 percent of the trainees passed only the flight test. 这题不会做555...大家能告诉我详细的解题思路么?作者: himba 时间: 2004-8-9 06:50
